Silicon Bilateral Switch IG04080 - Page 1
Forum section: electronics / beginners

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 22, 2023, 02:05:01 am
content: Needing assistance to recreate a IC with discrete components

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 22, 2023, 02:29:14 am
content: Test procedure:I used the following procedure to test the special Yamaha Silicon Bilateral Switch IG04080. It must be removed from the circuit board to test it. Use a bench power supply set at 12v, and put a 10k to 20k resistor in series with the positive output of the supply. (Assume you select a 12k resistor in series with the 12v supply)1) Connect the cold end of the 12k resistor to pins T1 and G on the IG04080. Connect the T2 pin to GND on the bench supply. With a voltmeter from T1/G to T2, it should show around 8v. Mine was 8.00v. I had expected about 9v, but 8v is better, and it is what it is.2) Reverse the connection of T1/G and T2. Connect the 12k resistor to T2 and ground T1/G. Again it should read 8v across the IG04080. Mine was 7.99V. This is amazingly close matching by the way.3) Connect the cold end of the 12k resistor to the T1 pin alone. Leave the G pin open circuit. Connect T2 to GND. Measure the voltage across T1 to T2. I expected it to be around 2.1v. Mine was around 1.3v.4) Reverse the connection of T1 and T2 leaving G open again. The result should be essentially the same as step 3 above.This procedure tests the internal diode bridge and Zener regulator first. Then tests the internal "SCR" breakover voltage. I believe that if the device under test passes this procedure, that it can be deemed to be OK.

author: Benta
author_rank: Super Contributor
timestamp: May 22, 2023, 11:49:40 pm
content: It shouldn't be hard to replicate as a discrete circuit, there's nothing IC specific (like double collectors).I don't even see any critical parts. TR1/TR3 and TR2/TR4 operate as thyristors.The purpose of the "G" terminal is not obvious.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 02:17:38 am
content: I sure would listen to your advice

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 02:25:20 am
content: More spec info attached

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 02:28:38 am
content: Additional spec information attached

author: Kim Christensen
author_rank: Super Contributor
timestamp: May 23, 2023, 02:38:56 am
content: Strange that in the datasheet, Yamaha describes "G" as ground... Looks more like a gate for triggering at a lower voltage to me.So does the competition.Because if you grounded the pin, then it would trigger at a much lower voltage.EDIT: To save other people from scrolling through a long thread, I did end up recreating a new PCB in KiCad to replace the IG04080.That post is here.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 02:43:54 am
content: I have more information that may help but the file is 18MB, not sure how to post that?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 01:13:02 pm
content: datasheet for TRIAC

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 01:26:33 pm
content: Schematic of Control Board

author: Benta
author_rank: Super Contributor
timestamp: May 23, 2023, 03:34:56 pm
content: I think it already is a discrete solution.Looking at the Yamaha data sheet, "Outline Drawing", it looks more like a module than a monolithic IC. Meaning a small ceramic substrate with discrete die and wire bonding. At the end epoxied into a plastic "box".

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 03:42:48 pm
content: Quote from: Benta on May 23, 2023, 03:34:56 pmCall it as you may, bottom line is finding a way to replace.

author: Benta
author_rank: Super Contributor
timestamp: May 23, 2023, 03:45:31 pm
content: Quote from: pulsed_power on May 23, 2023, 03:42:48 pmI just wanted to point out that if it's a module, the feasability of replacing it is high.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 03:50:59 pm
content: Quote from: Benta on May 23, 2023, 03:45:31 pmGood news?

author: Kim Christensen
author_rank: Super Contributor
timestamp: May 23, 2023, 04:26:52 pm
content: What connects to "SW" (lower end of R628) on the "Control C Board"? (Bottom left of schematic)Interesting that they've parallel a SCR and a TRIAC in that circuit (SCR601 & SCR602) and added diodes (D609 & D610) so the TRIAC only conducts in one direction.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 04:34:56 pm
content: Please see attached

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 08:07:03 pm
content: Quote from: Kim Christensen on May 23, 2023, 04:26:52 pmThat SW question threw me for a loop. It appears in some parts of the documents but not all. In my unit it was never installed.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 08:28:15 pm
content: An attempt to load the full schematic, not sure if it can viewed in detail

author: Kim Christensen
author_rank: Super Contributor
timestamp: May 23, 2023, 09:01:45 pm
content: Here's thelink to the PDF of your amplifier.(Or one very similar) They describe the power supply operation on pages 5-7...Might be useful for others following along.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 09:20:18 pm
content: I have the M-70. I couldn't find a way to upload the PDFThe B-6 has the same X Power Supply

author: schmitt trigger
author_rank: Super Contributor
timestamp: May 23, 2023, 10:10:16 pm
content: According to my trusty SCR Manual 5th Edition, by GE, the SBS functions quite similarly to a Diac, with the exception that the breakdown voltage is both much lower (about 8 volts instead of 30) and with a tighter tolerance and a reduced temperature coefficient.And just like the Diac, it is used as a trigger device in a phase control AC circuit.An additional advantage is the gate terminal, in which you can use it to trigger externally, emulating a N-gate SCR.GE produced a device, the 2N4991, which is still available from other sources.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 10:22:00 pm
content: GE produced a device, the 2N4991, which is still available from other sources.Do you think this 2N4991 will work as I need? External components?https://tinyurl.com/2gxxbjco

author: Benta
author_rank: Super Contributor
timestamp: May 23, 2023, 10:31:17 pm
content: The MBS4991 (Motorola) is more common and probably easier to find. GE hasn't made semiconductors since the 1970s.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 10:39:52 pm
content: https://tinyurl.com/2gxxbjco

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 23, 2023, 10:42:50 pm
content: Above simulation based upon my schematic

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 24, 2023, 05:41:35 pm
content: Any feedback on this possible replacement?

author: schmitt trigger
author_rank: Super Contributor
timestamp: May 24, 2023, 06:15:19 pm
content: In theory, it should work. Unfortunately the only way to know for sure, is to purchase one and try it out.BTW; Solid State Inc still makes the 2N4991

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 24, 2023, 06:22:21 pm
content: So you think the simulation is not of value?

author: Benta
author_rank: Super Contributor
timestamp: May 25, 2023, 04:03:48 pm
content: Just for fun, I sketched the discrete circuit in KiCAD and added manufacturer Spice models.Simulates beautifully and functions exactly as expected.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 25, 2023, 08:15:50 pm
content: This is the 3rd time I have posted thisMy simulation:https://tinyurl.com/2gxxbjcoFrom this schematic drawn in KiCad:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 25, 2023, 08:27:18 pm
content: What components did you select in your model?

author: Benta
author_rank: Super Contributor
timestamp: May 25, 2023, 08:53:44 pm
content: BC847, BC857, 1N4148W, BZX84C7V5. Models from Nexperia and Vishay.R1: 1k...10k, in this case 3k.R2, R3: 10k...100k, in this case 100k.R11: 1k, but it's just for current limiting in the sim. Ignore it.Schematics and simulaton:

author: Benta
author_rank: Super Contributor
timestamp: May 25, 2023, 08:58:19 pm
content: Quote from: pulsed_power on May 25, 2023, 08:15:50 pmI know. But that's not a simulation, it's a graphical toy.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 25, 2023, 09:02:36 pm
content: Very interesting, I had no idea.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 25, 2023, 09:12:29 pm
content: What about the G connection?

author: Benta
author_rank: Super Contributor
timestamp: May 25, 2023, 09:15:59 pm
content: Quote from: pulsed_power on May 25, 2023, 09:12:29 pmI ignored that for the sim. Add it to the schematic if you like. Its function in the full circuit is nebulous to say the least.Normally it's used to reduce the trigger voltage, but in this case...IDK.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 25, 2023, 10:04:31 pm
content: G = Gate Trigger Circuit?

author: Benta
author_rank: Super Contributor
timestamp: May 25, 2023, 10:39:13 pm
content: Quote from: pulsed_power on May 25, 2023, 10:04:31 pmI doubt it. The "GROUND" reference in the original Yamaha data sheet is probably correct, letting you disable the trigger by short-circuiting the Zener/bridge.But one thing is certain: it does not have the functionality of the 2N4991/MBS4991 gate input.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 26, 2023, 01:07:16 pm
content: Possible additional information

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 26, 2023, 01:08:43 pm
content: Possible additional information written text

author: Benta
author_rank: Super Contributor
timestamp: May 26, 2023, 07:09:19 pm
content: I'll step out here.The original question whether a discrete solution can be used to replace the IG04080 has been answered with: Yes. (because the Yamaha part alreadyisa discrete solution).Can it be replaced with a 2N4991/MBS4991? IMO: No. (the "G" pin functionality is completely different).The schematic/simulation I've provided does exactly what the Yamaha data sheet describes. You can build a small proto-board if you like to test it live.It's now system-wide troubleshooting, which is not my thing..I attach the KiCAD design files (V6.0) plus the Spice models if you'd like to play with them yourself.Cheers.EDIT: cosmetic correction to the schematic (Zener diode pinout+model, no functional change), .zip file replaced. Please use this version.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: May 26, 2023, 08:24:48 pm
content: Quote from: Benta on May 26, 2023, 07:09:19 pm

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 02, 2023, 12:29:27 pm
content: Quote from: pulsed_power on May 26, 2023, 01:08:43 pmWhile I am awaiting parts from DigiKey, I wanted to go back and readdress this alternate IG04080 design. Seeking feedback

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 06, 2023, 12:45:11 am
content: What is the function of R625, C605 & C606 in this circuit?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 06, 2023, 03:27:09 am
content: Quote from: pulsed_power on May 26, 2023, 01:07:16 pmPlease take a look at this functional description

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 08, 2023, 05:37:07 pm
content: Good news - No smoke and burnBad news - zero response 0vac

author: Benta
author_rank: Super Contributor
timestamp: June 08, 2023, 06:26:39 pm
content: Use a perf board instead. What you're doing there is fine for small-signal electronics, but has no place in a power supply with mains voltage.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 10, 2023, 04:03:28 pm
content: I have built the breadboard and the circuit passes the needed out of circuit test. It doesn't work when placed into the circuit. Zero response.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 10, 2023, 04:24:45 pm
content: Attempt to run in circuit

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 10, 2023, 04:41:38 pm
content: Doesn't this point to problems elsewhere in the power supply? Because you tested the IG04080at the beginning of this threadand it was OK, so building another out of discrete components doesn't really help.ie: You've replaced a good part with another good part. (Assuming you didn't make a mistake doing so) Therefore the fault is elsewhere.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 10, 2023, 05:15:09 pm
content: Quote from: Kim Christensen on June 10, 2023, 04:41:38 pmI am sorry for any misunderstanding, the IG04080 has been dead from the inception of this thread.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 10, 2023, 05:25:55 pm
content: Each and every component within the unit has been thoroughly tested. The technician that performed the test did not understand how to test the opto-coupler and the IG04080. Upon receiving the unit back from the technician, I was able to find support on the forums that located the test procedures. The opto-coupler tested fine but the IG04080 failed. Thus the journey began here for a replacement.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 10, 2023, 06:46:04 pm
content: Quote from: pulsed_power on June 10, 2023, 05:15:09 pmWhat were you testing in the comment that I linked?Curious as to which part of the test that the IG04080 failed... Was it a dead short, open, etc?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 02:52:07 am
content: Quote from: Kim Christensen on June 10, 2023, 06:46:04 pmYamaha produced four different models of amplifiers that used this IG04080. I don't know the production amount of these units but I think it would be safe to say the number is in the thousands. The IG04080 is the only part within the units that can't be sourced to make repairs to these units. These four models are considered some of the best units that were made in the years of production. Therefore I don't think I am the only person that would like to find a solution.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 11, 2023, 03:15:50 am
content: Quote from: pulsed_power on June 11, 2023, 02:52:07 amI see... You want to create a discrete module to replace a IG04080for others.So I assume you have a working IG04080 that functions in the amplifier you are using for your tests? (You say you don't. But then what did you test at the beginning? You still haven't answered that question)ie: Your current situation should be this: You put a working IG04080 into the Yamaha amplifier and it works fine. Then you substitute your breadboarded circuit and it doesn't work.The root of my question is: "How do we know if your Yamaha amplifier would work if a functional IG04080 was installed in it?"Without knowing with 100% certainty that this would be the case, trying to design, build, & test a discrete IG04080 using this amplifier would be a foolish errand. Doesn't matter if someone checked every component or not: You'd have no idea if the reassembled amplifier is functional at all.Just trying to do some basic troubleshooting so we're not running in circles. Your IG04080 looks OK to me. See your highlighted quote below:Quote from: pulsed_power on May 22, 2023, 02:29:14 am

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 12:14:11 pm
content: The opto-coupler tested fine but theIG04080 failed. Thus the journey began here for a replacement.The purpose of showing the test procedure was for the purposedefiningthe operating parameter's.My IG04080 is deadand I don't have a replacement, so yes this does create a handicap.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 12:20:48 pm
content: Without knowing with 100% certainty that this would be the caseThe only thing in life that is 100% certain is Death and Taxes

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 03:08:22 pm
content: I see... You want to create a discrete module to replace a IG04080 for others.I am in need to getmyunit back up and running and I think many others could benefit from this. Is that a bad thing?

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 11, 2023, 03:25:20 pm
content: Quote from: pulsed_power on June 11, 2023, 12:14:11 pmSo when you wrote "I" in the sentence,"Iused the following procedure to test the special Yamaha Silicon Bilateral Switch IG04080"and then said,"Minewas 8.00v", etc.. You were quoting someone else? A copy/paste from another website or something?That is the part I find confusing.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 03:50:09 pm
content: Info to date

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 03:51:18 pm
content: Quote from: Kim Christensen on June 11, 2023, 03:25:20 pm100% correct, once again sorry for any confusion

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 11, 2023, 05:56:32 pm
content: Quote from: pulsed_power on June 11, 2023, 03:51:18 pmOk, no problem. Now that we are on the same page, what are you doing with the red alligator jumper clips here? It looks like you are shorting out the LED on the opto-coupler. (TR606):

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 06:38:57 pm
content: See below for explanation of jumper

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 06:42:28 pm
content: ACV at Primary of Transformer V1 & GY

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 11, 2023, 07:09:39 pm
content: @120vac output on the variac the measured ACV at GY TI with DVM is 5.35vac

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 11, 2023, 07:31:06 pm
content: Quote from: pulsed_power on June 11, 2023, 07:09:39 pmLooks like it passes the test. Congrats!

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 14, 2023, 02:44:17 am
content: I don't know if this is within your scope of knowledge, but I am still having a issue:I am getting the proper 5.5vac at GY and VIBut at Orange and Blue I am getting 1.7vac, I think this should be 14vac to get 14vdc out of the rectifier

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 14, 2023, 02:55:41 am
content: Quote from: pulsed_power on June 14, 2023, 02:44:17 amIs this with the jumper still installed between TP1 and J605? I would guess that to be normal with the jumper installed. Remove that jumper and turn the power back on and see if you get 14Vdc out of the rectifier.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 14, 2023, 01:10:24 pm
content: @ Blue and Orange with fuses removed and jumper removedWith DVM 1.7vac

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 14, 2023, 03:06:48 pm
content: I had another person look at this Orange Blue connection on his unit, this is what he found

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 14, 2023, 04:26:11 pm
content: Quote from: pulsed_power on June 14, 2023, 01:10:24 pmI assume it is the same with the fuses installed...Check the +B and -B voltages on the "Control Circuit 1" PCB. Since that's the PCB which the regulates the voltages.Also, check the DC voltage across R623. This will tell us how much current is flowing through the LED of TR606... The more current that flows through the OPTO, the more AC voltage you should see on the Blue and Orange transformer wires. A voltage of zero across R623 would explain the low output. Then we'd just have to figure out why TR603, etc is not turning on.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 14, 2023, 05:47:02 pm
content: Quote from: Kim Christensen on June 14, 2023, 04:26:11 pmMeasure VDCbetween B+ and B-orGround to B+ and then B-?

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 14, 2023, 07:11:59 pm
content: Quote from: pulsed_power on June 14, 2023, 05:47:02 pmBetween B+ and B- seems more logical since the"Voltage variation detector circuit"doesn't appear to reference ground at all. (Doesn't hurt to know what B+ and B- are when referenced to ground. Plus, the voltages on the diagram are ground referenced.) Also measure between RS and B+ as well since that seems to be the voltage feedback path.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 14, 2023, 11:34:34 pm
content: Quote from: Kim Christensen on June 14, 2023, 07:11:59 pmB+ and B- between = 0vdcB+ to ground = 0vdcB- to ground - 0vdcSection B of the test is very confusing at best. In addition TR802 doesn't exist.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 12:03:23 am
content: Well, that's not good at all. Probably an issue in the "rectification circuit" because it looks like B+ and B- come from there. Can you provide a higher resolution of the schematic section shown below:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 12:52:23 am
content: The file size limitation in this forum is very frustrating, any ideas?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 12:59:03 am
content: The high res file is 16.6MB

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 02:31:56 am
content: I'm thinking if you posted a less than 3999KB version of the image below, rather than the full schematic you posted a few weeks ago, I'd be able to read it:Maybe something around 1800x1800 resolution will still be under the limit?If you wanted to post the full schematic in full resolution, you'd have to use a filesharing service like Google Drive or something and link to it.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 02:36:16 am
content: Quote from: Kim Christensen on June 15, 2023, 02:31:56 amI sent you my email, reply with your email and I will send you the file

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 02:55:20 am
content: filesharing service like Google DriveHow is that linked? How to link?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 03:03:48 am
content: https://drive.google.com/file/d/1ux1SgGZxMG8WvrP3b6kbqHbkuMMjw7mJ/view?usp=sharing

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 03:09:34 am
content: I sent a request for access... You can also share publicly if you want. "Anyone with the link" is the option I think.EDIT: Perfect. Got it!

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 04:02:11 am
content: Ok... The +B and -B definitely comes from the "Rectification Circuit" PCB which is fed AC from the main transformer.Looks like they sum the +HB (High voltage supply for amplifier) with the +LB (Lower voltage supply for amplifier) with two resistors (R807 & R805) to get the +B voltage that you are missing. They do the same with the negative supplies (-HB & -LB) with R808 and R806 to get the -B voltage. So either those resistors are burnt out, or those HB and LB voltages are missing on the "Rectification Circuit" PCB. I don't see any capacitors across the +B and -B lines that could be potentially shorted.So:Check the AC into the "Rectification Circuit" PCB. Use BL/EP as a 0V reference and measure RE & WH and BR & YE for AC volts.Then check the DC side by measuring +LB, -LB, +HB, -HB, for DC volts.Finally check the +B and -B on the "Rectification Circuit" PCB itself.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 04:23:24 am
content: Quote from: Kim Christensen on June 15, 2023, 04:02:11 amWe have already determined the voltages on the secondary side of the transformer are garbage.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 04:46:54 am
content: Quote from: pulsed_power on June 15, 2023, 04:23:24 amEven if they are "garbage" the voltages at +B and -B shouldnotbe zero. The only way for"the voltages on the secondary side of the transformerto not begarbage"is for current to flow in the OPTO (TR606) so that the SCRs conduct more and raise the voltages out of the "garbage" state. That can't happen if the voltages at -B and +B are zero.Theory of a similar amplifier explained here:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 03:02:00 pm
content: RE 3.3VACWH 3.3VACBR 2.36VACYE 2.38VAC+LB 9.43VDC-LB -9.42VDC+HB +15.55VDC-HB -15.55VDC+B 13.38VDC-B -13.29VDC

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 06:47:40 pm
content: Quote from: pulsed_power on June 14, 2023, 11:34:34 pmSince you measured the above at the "CONTROL CIRCUIT 1" PCB, but now you measure...Quote from: pulsed_power on June 15, 2023, 03:02:00 pmon the Rectification circuit (E.LYTIC CAP 1) PCB,is there a break in the path of the +B and -B wires between these two PCBs?Or has something changed since you measured yesterday?Can you now remeasure the following voltages directly on the "CONTROL CIRCUIT 1" PCB? I'm trying to analyze the circuit, so it would help to know the voltages at the following points on the "CONTROL CIRCUIT 1" PCB:+B-BRSOnce we know these 3 voltages, we should be able to sim it, or do the math, etc, to figure out if the OPTO should be driven or not.NOTE: All readings should be referenced to EP,BL,E On "E.LYTIC CAP" PCB or E or EP on "POWER CIRCUIT" PCB which seems to be the zero volt rail in this unit. Not sure if that's the same as the chassis ground or not. You could ohmmeter it to check to be sure.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 07:42:14 pm
content: Quote from: Kim Christensen on June 15, 2023, 06:47:40 pmSee pages 11 and 12 in the service manual

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 07:47:27 pm
content: B+/- were taken at this point this morning:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 08:18:45 pm
content: There are some parts issues going on with the Power Board:I don't think the correct subs were used, and I question the test results.TR701 spec 2SC2235 installed KSC2383TR702 spec 2SC1983 installed TIP122D702 spec 1D2C1 installed STTH1002CT

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 08:31:32 pm
content: Quote from: pulsed_power on June 15, 2023, 08:18:45 pmAlthough I don't think any of those items would have an effect upon the measurements you asked for today?

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 08:37:29 pm
content: Quote from: pulsed_power on June 15, 2023, 08:31:32 pmTR702 would have an effect since that's what controls the RS line which goes to the PCB I was asking about:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 08:44:14 pm
content: Quote from: pulsed_power on June 15, 2023, 07:42:14 pm

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 08:48:41 pm
content: The measurements taken this morning were using E as the test point groundPrior measurements were taken using G on CC2

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 09:06:01 pm
content: Are you waiting on me or am I waiting on you?

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 10:13:22 pm
content: Quote from: pulsed_power on June 15, 2023, 09:06:01 pmI'm basically waiting on you to find out what the voltage is on RS... Interestingly enough, you were waiting for that too:Quote from: pulsed_power on June 14, 2023, 11:34:34 pmSection B of the test mentions measuring RS also. I believe TR802 in the manual is a typo. I think they mean TR702.What part of section B of the test do you find confusing? Screen shot below for reference:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 10:50:32 pm
content: Reply to post #89?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 10:59:15 pm
content: Quote from: Kim Christensen on June 15, 2023, 10:13:22 pmStates it should be 0Then states if 0 check partsMy memory recalls that RS was at 1.56vTR702 measures a hfe of 39, should be above 2000, I must question if the DCA75 is measuring this type of device correctly.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 15, 2023, 11:04:54 pm
content: I think RS is the protection circuit on the outputs. If any DC on the rails is present the relays drop out.PS: I have no LED's working and the Relays are not turning on. One of those LED's is the Protection.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 15, 2023, 11:24:39 pm
content: Quote from: pulsed_power on June 15, 2023, 10:59:15 pmWhat they are saying is, when the unit is powered with 120VAC:If RS isnear zero volts(working properly)andthere is 1.2V across R623, then all is well.ORIf RS isnear zero volts(working properly)andthere is 0V across R623, then TR601, TR604, or D601 are most likely to be bad.ORIf RS iswell above zero volts(not working properly)andthere is 0V across R623, then the fault is most likely with TR702.Note: Take these fault finding hints with a grain of salt. They don't cover all possibilities and there are plenty of other things that could result in 0V being across R623.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 16, 2023, 12:25:33 am
content: Quote from: pulsed_power on June 15, 2023, 10:59:15 pm1.56V seems a bit high. I would expect it to be less than 1V or so. Not sure how much collector current it is passing. If it passing around 2 amps, then 1.56V would be normal in my mind.Your DCA75 does identify it as a Darlington. I'm not really familiar with the DCA75, but the built in resistors in the TIP122 might be fooling it. Plus these testers generally don't provide enough current/voltage to properly test power devices. Probably because then you'd be blowing up small signal transistors with it.Quote from: pulsed_power on June 15, 2023, 08:18:45 pmSeems OK: spec 2SC2235 installed KSC2383They do come in different hFE specs though. Depends of part number suffix:KSC2383: R: 60-120, O: 100-200, Y: 160-3202SC2235: O: 80-160, Y: 120-240Both TIP122 & 2SC1983 are Darlingtons with aprox the same specs. Though the TIP122 has built in base-emitter resistors which may effect circuit operation a bit. Spec sheet for 2SC1983 doesn't mention any.Diodes seem OK: spec 1D2C1 installed STTH1002CTEDIT: See my reply about "section B of the test" on the previous page

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 16, 2023, 08:45:39 pm
content: Current status:B+ = 13.65VDCB- = -13.65VDCRS = 0.67VDCAll measurements must use E on Electrolytic Board for negative DVM probe.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 16, 2023, 10:33:18 pm
content: It looks like the OPTO should be getting about 2.2mA if the circuit was operating properly.ie: The voltage across R623 should not be zero when B+ = 13.65VDC, B- = -13.65VDC, and RS = 0.67VDC. In that state we should be seeing around 2V across R623.You could try simulating the circuit. I've done it manually, made a few assumptions, but I believe it should be correct/close:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 16, 2023, 10:57:45 pm
content: The orange text adjacent to the transistors is what Yamaha says the values should be. I looked at these voltages with the DVM and what I saw was much different. I am still confused where the measurements ground point should be taken.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 16, 2023, 11:47:14 pm
content: Quote from: Kim Christensen on June 16, 2023, 10:33:18 pmTP1 to B- = 0.00vdc

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 17, 2023, 12:04:41 am
content: There is a method to my madness:The voltages, what Yamaha says they should be, are only valid if the amplifier was operating normally. Right now it's not.Normally, B+ is around 52VDC and B- is around -54VDCbut because there is a fault somewhere, they are B+ = 13.65VDC and B- = -13.65VDC.This means that all the other voltages marked by Yamaha on the CC1 PCB are currently invalid and cannot be used for trouble shooting. So what I did is calculate what they would be when fed with a much lower voltage.Now we can figure out why there is zero volts across R623 (TP1 to B- = 0.00vdc). Therefore I have some more measurements for you to do.What's the voltageacrosseach of these components:D604 & D603 (they should be forward biased with about 0.6-0.7V drop each)R612 (Should be around 0.6-0.7V)D601R605R607 (This will be in millivolts)R606 (This will be in millivolts)Between TR601 collector and E on Electrolytic Board.That should be enough for now. What you measure will determine the next direction we should take.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 01:06:58 am
content: D604 & D603 (they should be forward biased with about 0.6-0.7V drop each)14.83 – 15.1515.06 – 14.84R612 (Should be around 0.6-0.7V)15.2 – 15.24D60115.3 – 15.11R60515.3 – 15.3R607 (This will be in millivolts)6.25 – 6.22R606 (This will be in millivolts)6.24 – 6.3Between TR601 collector and E on Electrolytic Board.6.26

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 01:28:50 am
content: By the way: You are the first person I have come across in this Audio service business that has the talents to TRULY understand how to analyze a circuit. A true Blessing!And it has been a very long (years) and in-depth search!

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 17, 2023, 03:13:56 am
content: Quote from: Kim Christensen on June 17, 2023, 12:04:41 amQuote from: pulsed_power on June 17, 2023, 01:06:58 amOk... I think I might have confused you a bit. What I meant here by "across" was to put the negative lead of your DMM on the cathode of D604 and the positive lead of the DMM on the anode of D604.Then do the same for D603. (negative lead on the cathode of D603 and the positive lead of the DMM on the anode of D603)And do all the other components the same sort of way by putting your DMM across them andnotany meter lead to E on Electrolytic Board at all.Except for the last component, TR601 collector, which I want referenced to E.The problem with measuring the way you did is if +B and -B are bouncing around a bit, then we may not get a true reading of what is across D604 for example, because the readings on both ends are fluctuating and we are getting readings from different periods of time.But, our little mishap makes me wonder. You measured a positive voltage of 14.83 – 15.15 on D603? Not a negative voltage of -14.83 and -15.15? Because if -B is -13.65, anywhere around that number, then the cathode of D604 should be exactly the same as the voltage on -B. So this make me wonder what happened.So I'm going to have to ask if you could do it again as I described. But before you do, make sure +B and -B on the CC1 board really are still around +13.65 and -13.65 relative to E and that RS on the CC1 board is still measuring around 0.67V relative to E. (Before checking any other voltages on the CC1 PCB, you should check these 3 voltages just to make sure you're not going down a rabbit hole)

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 09:33:48 am
content: Measurements were taken one side of component to G and then the other side of the component to GD604 & D603 (they should be forward biased with about 0.6-0.7V drop each)14.83 – 15.15 = 0.32v drop15.06 – 14.84 = 0.22v dropR612 (Should be around 0.6-0.7V)15.2 – 15.24 = 0.02v dropD60115.3 – 15.11 = 0.19v dropR60515.3 – 15.3 = 0.00v dropR607 (This will be in millivolts)6.25 – 6.22 = 0.03v dropR606 (This will be in millivolts)6.24 – 6.3 = 0.06v dropBetween TR601 collector and E on Electrolytic Board.6.26

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 09:37:47 am
content: In addition I found out why the E and G were giving different voltage values. The G was to be connected to the case for ground, when I pulled the boards from the case to gain access for measurements I forgot to reconnect the G back to the case.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 09:47:20 am
content: So I'm going to have to ask if you could do it again as I described. But before you do, make sure +B and -B on the CC1 board really are still around +13.65 and -13.65 relative to E and that RS on the CC1 board is still measuring around 0.67V relative to E. (Before checking any other voltages on the CC1 PCB, you should check these 3 voltages just to make sure you're not going down a rabbit hole)I did notice that B+ to E is a +v and B- to E is a +v, I counted it off as being tired and possibly doing something incorrect. I will look at this again in the morning.

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 17, 2023, 04:25:36 pm
content: Quote from: pulsed_power on June 17, 2023, 09:33:48 amHere's the reason I would like you to measure directly across the components as well as to ground/0V (Instead of doing the math to get the voltage across it). This is especially true for R606 and R607 where the voltages will be very small.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 04:47:06 pm
content: Quote from: Kim Christensen on June 17, 2023, 03:13:56 amB+ = +14.08vdcB- = +14.04vdcRS = 0.675vdcD603 0.022vdcD604 = 0.007vdcR612 = 0.00vdcD601 = 0.007vdcR605 = 0.00vdcR607 = 0.00vdcR606 = 0.00vdc

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 04:54:44 pm
content: I did notice that B+ to E is a +v and B- to E is a +v, I counted it off as being tired and possibly doing something incorrect. I will look at this again in the morning.I checked this again this morning and I am not seeing a -vdc at B-

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 17, 2023, 05:55:56 pm
content: Quote from: pulsed_power on June 17, 2023, 04:54:44 pmQuoteOK... Something must have changed since then.-B is derived from -LB and -HB voltages on the "E.LYTIC CAP1" PCB so check those voltages again. Ina previous postyou had measured them and gotten this:+LB 9.43VDC-LB -9.42VDC+HB +15.55VDC-HB -15.55VDC+B 13.38VDC-B -13.29VDCSo either those voltages (-LB -HB) are missing, or you have a short to ground on -B, or the resistors R806 & R808 are bad.EDIT: Or the -B wire is open/broken between the "E.LYTIC CAP1" PCB and "POWER CIRCUIT" PCB or between the "POWER CIRCUIT" PCB and "CONTROL CIRCUIT 1" PCB.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 07:28:49 pm
content: Quote from: Kim Christensen on June 17, 2023, 05:55:56 pmPlease take a look at your email

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 17, 2023, 08:06:08 pm
content: QuoteYikes! That's quite the birds nest of wiring.It's going to take some thorough inspecting to make sure you find all the shorts and broken connections.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 08:36:01 pm
content: Quote from: Kim Christensen on June 17, 2023, 08:06:08 pmI have disliked those wire wrap connections since me early days (72, 72, 73 & 74) of working for Motorola Two-Way Communications as a Field Service Tech.I have tried a couple different ways to dispose of them and try a different style connection but they have their downfalls. Maybe you have some thoughts on this?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 08:56:47 pm
content: Quote from: pulsed_power on June 17, 2023, 08:36:01 pm

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 17, 2023, 10:11:22 pm
content: The use of ferrules with the screw terminals looks pretty good to me. At least this makes it easier to remove the PCB for servicing in the future.Though you may want to be careful and place an insulating piece between the screw terminals that are very close together. +LB and +P look a bit too close in this photo:Also, if they were all screw terminals, I don't know how you'd insert a ferrule/wire into -P. In addition, a wire inserted too far into -LB would short to -P...In the case of the photo above, I'd probably solder the wires/ferrules direct to LB, -P, and GY and connect the other ends to the mating PCB with screw terminals.-B, +B, +LB, +P and VI would be screw terminals. It would take some planning so a board could be removed without any desoldering.EDIT: The downside I see with the screw connectors is the torque imposed on the solder pads could break the pads loose when tightening/loosening the screw. The alternative would be to find a PCB connector that fits with the hole size & spacing that you have. It could get pricey for good connectors. The old stuff they wire wrapped to, almost looked like the old Molex connectors which I never was a big fan of.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: June 17, 2023, 10:47:52 pm
content: EDIT: The downside I see with the screw connectors is the torque imposed on the solder pads could break the pads loose when tightening/loosening the screw.From my previous experience that is the#1 problem. A great deal of stress is also applied from the wire itself. If the connector had a compression method against the board that would be the ticket, I have not located such a connector.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 06, 2023, 07:56:19 pm
content: After a wonderful two week vacation, I received the IG08040 yesterday with great pleasure. Now I am working on that wire disaster.

author: VintageAudio
author_rank: Newbie
timestamp: July 09, 2023, 10:24:22 am
content: I was quietly following this thread as I have a similar issue and was unable to find a replacement part for the IG04080. Can you tell me , is this a drop in replacement with the same functionality?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 06:50:11 pm
content: I am very sad to find the new IG04080 doesn't work, no power on.I managed to find a working M70 Amp with a working IG04080 in it and took some measurements:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 06:51:05 pm
content: I tested the IG04080 in the working M70.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 07:19:07 pm
content: Pin #T1

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 07:19:52 pm
content: Pin G

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 07:20:40 pm
content: Pin #T2

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 10, 2023, 08:16:18 pm
content: Quote from: pulsed_power on July 10, 2023, 06:50:11 pmTo clarify:You took some scope measurements from a "working M70 Amp"...Then you put your newly made IG04080 PCB into the very same "working M70 Amp" and now it doesn't work?EDIT can you post the schematic file, or a screenshot of it, of your IG04080 PCB design? I looked at the photo you posted and it looks odd but it's hard to say for sure.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 08:55:17 pm
content: Then you put your newly made IG04080 PCB into the very same "working M70 Amp" and now it doesn't work? Correct the IG04080 did not work.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 08:57:35 pm
content: Quote from: Kim Christensen on July 10, 2023, 08:16:18 pm

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 09:08:44 pm
content: Better photo attached

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 09:23:52 pm
content: BC847, BC857, 1N4148W, BZX84C7V5. Models from Nexperia and Vishay.R1: 1k...10k, in this case 3k.R2, R3: 10k...100k, in this case 100k.R11: 1k, but it's just for current limiting in the sim. Ignore it.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 09:37:18 pm
content: Quote from: pulsed_power on July 10, 2023, 09:08:44 pm

author: Benta
author_rank: Super Contributor
timestamp: July 10, 2023, 09:54:40 pm
content: You need to check your parts list again:13t = BC846BPN -> OKA7 = BAV99 -> OKR1 = 4k7 -> OKR2, R3 = 4k7 ->very lowH2 = MMSZ5242 ->12 V Zener, not 7.5 VA credit for artwork and simulation would be nice.Also, I don't think it's a good idea to put a Yamaha logo on your own product.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 10:52:16 pm
content: Quote from: Benta on July 10, 2023, 09:54:40 pmThe efforts of so many people have gone into this, not just a single person. Your assistance has also been outstanding and much appreciated.The person that placed the final order put the Yamaha label on it, since the part has been out of production for over 40 years, I never gave it a second thought.

author: Benta
author_rank: Super Contributor
timestamp: July 10, 2023, 11:10:56 pm
content: Quote from: pulsed_power on July 10, 2023, 10:52:16 pmHey, don't think I'm a primadonna here. My reply was specific to #134.Check that Zener instead.Cheers.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 11:18:28 pm
content: Quote from: Benta on July 10, 2023, 11:10:56 pmAs I stated: Your assistance has also been outstanding and much appreciated.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 11:21:32 pm
content: Quote from: Benta on July 10, 2023, 11:10:56 pmI sent your message to Jason to review the Zener and Resistor concern you have

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 10, 2023, 11:43:07 pm
content: You could connect your T1 & T2 of your new PCB to low voltage AC supply or sig-gen with a series resistor to limit the current. Then see if you get the same sort of waveform you got in the SIM.One other thing. Hard to tell from the photo, but:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 10, 2023, 11:58:42 pm
content: Quote from: Kim Christensen on July 10, 2023, 11:43:07 pmI was just thinking about using the same test procedure that I conducted on the original IG04080. I can also do as you have defined.Testing to see if these points are connected is far beyond my old age eye sight.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 12:08:36 am
content: Quote from: pulsed_power on July 10, 2023, 11:58:42 pmIt looks like there are some traces on the back side:

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 11, 2023, 12:10:36 am
content: Quote from: pulsed_power on July 10, 2023, 11:58:42 pmJust use an ohm meter. Trace could be hidden under the part. I can see the other 3 base<-->collector connections in the photo. Just not that one.EDIT: those backside traces look too long for that connection. Since the pins are side by side you'd think it would be on the topside.But sometimes PCB auto-routers are insane.Quote from: pulsed_power on July 10, 2023, 11:58:42 pmThat'll work too. You'll also figure out the zener voltage by doing that test.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 12:31:02 am
content: With my vision and nerves I don't think I could put a Ohm Meter on those contact points.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 04:15:03 pm
content: Quote from: Kim Christensen on July 10, 2023, 11:43:07 pmConnect T1 & T2 to sig-gen - OKConnect Scope @ what locations?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 04:38:11 pm
content: Test procedure:I used the following procedure to test the special Yamaha Silicon Bilateral Switch IG04080. It must be removed from the circuit board to test it. Use a bench power supply set at 12v, and put a 10k to 20k resistor in series with the positive output of the supply. (Assume you select a 12k resistor in series with the 12v supply)1) Connect the cold end of the 12k resistor to pins T1 and G on the IG04080. Connect the T2 pin to GND on the bench supply. With a voltmeter from T1/G to T2, it should show around 8v.Mine was 8.46v. I had expected about 9v, but 8v is better, and it is what it is.2) Reverse the connection of T1/G and T2. Connect the 12k resistor to T2 and ground T1/G. Again it should read 8v across the IG04080.Mine was 8.72V. This is amazingly close matching by the way.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 04:54:44 pm
content: 3) Connect the cold end of the 12k resistor to the T1 pin alone. Leave the G pin open circuit. Connect T2 to GND. Measure the voltage across T1 to T2. I expected it to be around 2.1v.Mine was around 1.28v4) Reverse the connection of T1 and T2 leaving G open again. The result should be essentially the same as step 3 above.Mine was 4.46v

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 05:16:10 pm
content: Connection of sig-gen to IG04080

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 05:22:30 pm
content: I have that working M70 and thinking about pulling the power supply boards and placing into the not working M70, but that worries me that I could kill the working boards.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 05:38:14 pm
content: Now I went back and pulled the IG04080 out of the working M70 and tested it with the sig-gen, no effect what so ever to the sine wave.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 11, 2023, 07:05:23 pm
content: Quote from: pulsed_power on July 11, 2023, 04:54:44 pmSomething is definitely amiss. The voltages should be symmetrical. Both should have been around 2v or less.Quote from: pulsed_power on July 11, 2023, 05:38:14 pmSo this IG04080 is the one that works in the M70?ie:Notthe one you had made...Hmmm... If so, that seems odd indeed.Quote from: pulsed_power on July 11, 2023, 04:15:03 pmLike this:

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 11, 2023, 07:37:47 pm
content: I think that I might have found a problem with your PCB. Not 100% sure without the PCB in front of me and not being able to ring out the connections, but it looks like you need to rotate one of the dual transistor packages:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 08:01:14 pm
content: Quote from: Kim Christensen on July 11, 2023, 07:05:23 pm

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 08:52:29 pm
content: Quote from: Kim Christensen on July 11, 2023, 07:37:47 pmI don't think there is any way I can pull that transistor to rotate, just don't have the equipment, eye sight and steady hand.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 11, 2023, 09:53:48 pm
content: Quote from: pulsed_power on July 11, 2023, 08:52:29 pmSince you had 30 of these produced, that's going to be "fun"...You have 2 choices then: Get someone else to do it or order a new batch with the correct placement.Quote from: pulsed_power on July 10, 2023, 11:00:32 pmGet "ithinkido" to send you the files he uploaded to JLCPCB so we can see exactly how it's laid out. That way we can be 100% sure that we get your PCB fixed properly and catch any other problems before you order new ones or get someone to rework them. It would suck if there was another issue that we've missed because we can't see the layout.Or even some exported PNGs of all PCB layers, schematic, etc, from those same files (final drawings) would help too.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 11, 2023, 10:22:42 pm
content: Quote from: pulsed_power on July 11, 2023, 05:38:14 pmSwitch your scope to GND and center the trace. Then switch to DC. You need to adjust the signal generator to output 24V pk-pk... ie: The sine wave needs to swing to +12V on the positive peak and to -12V on the negative peak.What I'm seeing on your scope is only around 16V pk-pk (Around 8V max voltage in either polarity) which is not enough to trigger the IG04080 via the resistor.

author: Benta
author_rank: Super Contributor
timestamp: July 11, 2023, 10:28:27 pm
content: And if the Zener is indeed a 12 V type, it won't trigger at all. In that case, you'll need 35...40 VPP, which very few signal generators can supply.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 11:07:12 pm
content: Quote from: Kim Christensen on July 11, 2023, 10:22:42 pmAs requested

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 11, 2023, 11:25:09 pm
content: Quote from: pulsed_power on July 11, 2023, 11:07:12 pmAC level still is too low (Seeing less than 15V peak to peak). It's probably distorted because of the reversed duo-transistor pair. What's the waveform directly out of the sig gen look like? It should be 24V peak to peak centered around 0V.What does theworking IG04080that was out of the good M70 look like in this test setup?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 11:30:01 pm
content: Quote from: Kim Christensen on July 11, 2023, 11:25:09 pmTesting of original

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 11, 2023, 11:41:10 pm
content: This forum has gone crazy with kicking me out and then not displaying correctly

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 11, 2023, 11:45:49 pm
content: Quote from: pulsed_power on July 11, 2023, 11:30:01 pmThat looks great! Exactly what we should be seeing.Out of circuit, what resistance do you measure between T1 and G of the original? If it's the same as your replacement PCB you should see around 4.7K. Measure in both directions to see if the readings are the same. The B-E junctions of the transistors may mess up the reading a bit so try your ohm meter on the higher resistance ranges such as 200K & 20K. On the lower ranges, the Vbe drop of the transistors will dominate.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 12, 2023, 12:13:03 am
content: Quote from: Kim Christensen on July 11, 2023, 11:45:49 pmOriginal is 8KNew is 4.7K

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 12, 2023, 12:21:22 am
content: One more attempt without distractionOriginalT1 - G = 8.04kT2 - G = openNewT1 - G = 4.7kT2 - G = 4.7k

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 12, 2023, 12:47:13 am
content: Looks like those new replacement PCBs should have some higher value resistors in them. Maybe 8.2K instead of the 4.7K.Curious as to why the new one has a resistance of 4.7K between T2 and G instead of reading open... Do the other PCBs also have this ohm reading too? Now I really want to see those PCB layer CAD images. Something is not right because you shouldn't read 4.7K between T2 and G at all if they are built like you ordered.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 12, 2023, 12:55:23 am
content: Quote from: Kim Christensen on July 12, 2023, 12:47:13 amT1+ / G- = 4.7KT1- / G+ = 4.7KT2+ / G- = 48KT2- / G+ = OPEN

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 12, 2023, 02:06:26 am
content: Quote from: pulsed_power on July 12, 2023, 12:55:23 amLooks like the one you tried in the M70 (new PCB) was damaged by the experience. I assume the duo-transistor pairs on the new PCBs are all installed in the same orientation as the one you trialed? Because the duo-transistor pair was installed in reverse, some components might have failed shorted due to excess current flow. That might explain the 4.7K between T2 and G on that one PCB.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 12, 2023, 07:36:01 am
content: Message from Jason who had the PCB's built:I have checked with the manufacture and it is correct, one of the dual transistor packages was paced 180 rotated.I will have a new batch sent

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 12, 2023, 07:07:14 pm
content: Well it looks like I am now back to ground zero. Any suggestions?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 12, 2023, 08:09:10 pm
content: Quote from: pulsed_power on July 12, 2023, 07:36:01 amSince I mentioned his name and posted items that he feels were not appropriate he has stopped any continued efforts.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 12, 2023, 10:38:58 pm
content: Quote from: pulsed_power on July 12, 2023, 08:09:10 pmThat seems a bit silly. It's not like you said anything really bad about him. The quote: "I will have a new batch sent" puts him in a good light and he should follow through on that in my opinion.Quote from: pulsed_power on July 12, 2023, 07:07:14 pmSee if you can find someone local who can rework one or two unused boards for you. With a hot-air tool and tweezers it should be possible to rotate that part without destroying it.If they don't have fancy tools, they could blob it off with larger soldering tip, clean the lands with braid/wick, and then solder a new part on in the correct orientation.Then, once you know you have a working unit and all the kinks are worked out, you can look at ordering more PCBs.Convince Jason to give you the original CAD files, so you can contract someone else to fix that minor error in the Pick and Place file and request a new batch. I wouldn't wait too long with this. Do it while it's fresh in both your minds rather than asking a month from now.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 14, 2023, 03:42:14 am
content: While you have theoriginal IG04080out of circuit, you should test it to see what current it triggers and releases at. This could be helpful information for future trouble shooting.Increase supply voltage until the uA meter starts showing a sharp current increase. Slow down and note the current justbeforethe LED brightens and the voltage drops across the 04080. Then lower the supply voltage and note the current justbeforethe LED goes out and the voltage increases across the 04080:

author: RES
author_rank: Regular Contributor
timestamp: July 14, 2023, 09:48:15 am
content: Can't you "just" create the same principle by using a dual SPDT analog switch ic?... e.g like the DG387B. Join the CMOS inputs, create a make-before-break / break-before-make) switch?https://www.vishay.com/docs/71404/71404.pdf

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 14, 2023, 04:15:35 pm
content: Quote from: Kim Christensen on July 14, 2023, 03:42:14 amAre you sure about that? I am not seeing that type of response.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 14, 2023, 04:44:20 pm
content: Quote from: pulsed_power on July 14, 2023, 04:15:35 pmYou have to adjust the supply voltage really slowly as you approach the trigger and release points. You can see the effects on your scope trace:EDIT: Where I say "Turns on" I mean the IG04080 as a unit. ie: The transistor pair latches on.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 14, 2023, 05:19:15 pm
content: But that is a AC Voltage shown on the scopeI would need a AC Amp meter in conjunction with the scope?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 14, 2023, 06:34:37 pm
content: Also thank you for the explanation on the waveform. it is what I thought but it is nice to receive a confirmation.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 14, 2023, 07:27:06 pm
content: You could do it with the scope, but my original idea was using a power supply.Here's how you could do it with a scope. Use a 10K resistor and measure the voltage drop across it to figure out the current. With the scope set to 1V/Div across 10K the vertical scale will be 100uA per division.Ignore my pk-pk voltages. I used a 6V zener in my circuit and an AC transformer instead of a sig gen so the peak voltage is higher but the trigger level is lower. But the general waveform shape should be the similar for you.

author: Benta
author_rank: Super Contributor
timestamp: July 14, 2023, 07:44:19 pm
content: 10k is far too high. When the SBS triggers, internal resistance is 4.7k.1k would work.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 14, 2023, 07:58:59 pm
content: It seems to work though. The 4.7K is across the base-emitter junction of the transistors, therefore you only need around 150uA to get 0.7V across that resistor. That means you'll only have 1.5V across the 10K at that point. A bit more current, and the transistor pair will latch on which is what happened in my test. (I was using 8.2K resistors in my 04080 circuit because 8K was measured between G & T1 on the authentic Yamaha part)Changing the resistors in the circuit, while it doesn't change the trigger voltage across T1 & T2, it definitely defines the max current drawn just before the trigger point. Hence this test.EDIT: Actually, there are two current paths that need to be satisfied before the circuit will trigger. Shown below is for when T1 is positive relative to T2. As the voltage across R1 rises due to the zener conducting, Q4 will start to draw current and current will also flow in R3. So 0.6V across 8.2K = 73uA but since we must satisfy both the red and blue path, the trigger current must be double that at 146uA, which explains my readings a bit better. With 4.7K resistors, the trigger current would be around 255uA or so.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 14, 2023, 10:02:02 pm
content: I haven't done a lot of hot air rework, but you should be able to put some flux on the pads, place the part, and then use the hot air to reflow it. (The old solder should still be on the pads/part)If the hot air flow is gentle enough not to blow the part away, then the surface tension of the solder should pull the part into the proper orientation (Within reason). You can also hold & then nudge it with a non magnetic stick if it's off center. It's kind of hard not to reflow parts next to it, but generally that's not a problem.If the pads have been cleaned off of solder, usually what you do is put some SMD solder paste (Mix of flux and solder granules) on the pads and stick the part on top. Then use the hot air to solder it.EDIT: Hmmm... Not sure where the comment that I was relying to went... But I'll leave this here anyways.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 14, 2023, 11:05:38 pm
content: I tried and just destroyed 3 boards.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 14, 2023, 11:20:48 pm
content: Ouch. Find some junk PCBs to practice on. Looks like you have at least 3 available.Practice moving the other parts around on those after watching some video tutorials. Maybe you need some Optivisors, or other magnifiers, to see what you're doing?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 14, 2023, 11:26:55 pm
content: Just too small I thought my first attempt was going to work and then realized I had lifted a resistor. Lost resistor, tried 2nd board and everything is sliding around. 3rd board went further down hill.I have it very well lit, have the board in a proper holding device, using tweezers also a strong magnification. Just can't control the heat spread.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 14, 2023, 11:42:19 pm
content: I guess I am back to my original approach of learning Kicad to create files that can be sent to a fabricator. I did manage to create a schematic in Kicad but can't figure out how to get it into a PCB.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 14, 2023, 11:58:01 pm
content: You're best to ask in theKiCad section of the forum. Are you going to make it out of through hole parts instead?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 12:26:06 am
content: So close yet so far. I am going to go back to that wiring issue and see what may come forward on finding resources to modify the boards I have.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 15, 2023, 02:22:13 am
content: Test your authentic IG04080 using thetest you described at the very beginningof this thread.Then test it's trigger currentas I mentioned earlier.If the current is around 150uA; you'll build your circuit using 8.2k resistors. If it's around 255uA; 4.7K resistors. Etc.Then use the above info to build a IG04080 on a breadboard and test it using the above two methods to ensure the design is correct.Then build that circuit on a perf-board using the same through-hole components as the breadboard circuit. Test it as above.Then put the perf-board circuit into the working M70 and see if it works.Only then should you go into KiCad and layout a PCB and order them.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 04:45:47 pm
content: Test with 10k

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 05:05:04 pm
content: Change in sig-gen frequency

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 05:23:53 pm
content: My screw up! Wrong resistors being used!The original breadboard used 100k resistors as shown in the photos.I now went back and tried 4.7k and 8.2k, the breadboard circuit didn't like either and has stopped working. I need to clear my mind from another attempt at those SMD rework :'(

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 15, 2023, 07:46:00 pm
content: Quote from: pulsed_power on July 15, 2023, 04:45:47 pmIs this trace from the authentic Yamaha part or from the breadboard circuit made with 100K resistors?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 07:59:43 pm
content: breadboard circuit made with 100K resistors

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 10:00:00 pm
content: 8.2k @ R1, R2 & R3

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 10:00:43 pm
content: 4.7k @R1, R2, R3

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 15, 2023, 10:13:19 pm
content: Quote from: pulsed_power on July 15, 2023, 07:59:43 pmWhat transistors are you using? Maybe their gain is really low or something. (Just saw your latest post... That looks better) I used MPSA06 and PN2907A transistors and measured the trigger current using the circuit below:These are the traces I got from swapping the 3 resistors between different values. As you can see, I can change the trigger current quite consistently with different values:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 10:20:36 pm
content: Quote from: Kim Christensen on July 15, 2023, 10:13:19 pm547 & 557

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 10:21:57 pm
content: IG04080 test

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 15, 2023, 10:24:25 pm
content: Quote from: pulsed_power on July 15, 2023, 10:21:57 pmThat looks a lot like the 8.2K test... So that's probably the resistor values you should be using. You could zoom in (1V/Div instead of 5V/Div) to get a better idea of the trigger current level.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 10:26:02 pm
content: Quote from: Kim Christensen on July 15, 2023, 10:24:25 pmI was just noticing your scope photos, I was giving the incorrect view

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 10:30:51 pm
content: Let's try this

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 15, 2023, 10:39:52 pm
content: Looks good. Triggering at around 140uA. Time to build a 8.2K version on a perf-board, test it, and then try it in your known working M70.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 15, 2023, 11:23:33 pm
content: This should work?https://www.amazon.com/dp/B07NM68FXK?psc=1&smid=AMIHZKLK542FQ&ref_=chk_typ_imgToDp

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 15, 2023, 11:57:14 pm
content: Yup. That'll work fine for a prototype as long as the quality is decent. Looks OK to me.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 17, 2023, 07:42:31 pm
content: Is this the correct resistor for this application:594-MCS04020C8201FE0

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 17, 2023, 07:59:13 pm
content: That'll work for the final PCB... But 0402 SMD is kind of tiny. You might want to go with a bigger size/wattage, not because it needs it, but so it's easier to rework if required. Maybe size 0805?Does this mean that you've already built the perf-board proto-type and successfully tested it in the M70?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 17, 2023, 08:17:26 pm
content: Quote from: Kim Christensen on July 17, 2023, 07:59:13 pmI just received the parts order which included flux in a syringe, thought I would try that repair again first

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 17, 2023, 09:08:22 pm
content: The existing resistors appear to be 2mm L x 1mm W, maybe a little less.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 17, 2023, 09:23:36 pm
content: 0603 size are 1.55mm x 0.85mm.0805 size are 2.0mm x 1.25mm.So those 0402 (1.0mm x 0.5mm) are going to be a bit small for the pads. Might still be able to bridge the gap with a bit of extra solder. Sometimes you can fit SMD resistors on pads designed for one size larger.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 18, 2023, 07:44:05 pm
content: Doesn't look the same

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 18, 2023, 08:12:03 pm
content: Same circuit worked on the bread board though. Can't see all the wiring and part numbers, but:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 18, 2023, 08:20:14 pm
content: Quote from: Kim Christensen on July 18, 2023, 08:12:03 pmTook parts off of breadboard

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 18, 2023, 08:21:20 pm
content: Quote from: Kim Christensen on July 18, 2023, 08:12:03 pmIt is connected

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 18, 2023, 08:25:57 pm
content: Test configuration

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 18, 2023, 08:52:08 pm
content: Might want to check you connections on the back of the perfboard. There appear to be a few danglers that go nowhere. Can't see all due to resolution of photo:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 18, 2023, 09:07:10 pm
content: Better photos of rear side

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 18, 2023, 10:30:27 pm
content: Kind of hard to follow from pictures, but it looks mis-wired. Best to just ohm-meter all the connections from the topside to see if you've got it right.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 18, 2023, 11:17:27 pm
content: Quote from: Kim Christensen on July 18, 2023, 10:30:27 pmI tied the diodes to the top of R1 and it should be connected to the bottom of R1Thank You

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 12:32:23 am
content: Quote from: pulsed_power on July 18, 2023, 11:17:27 pmI also found Q3 & Q4 wiring is incorrect. Got to give it a break for the night.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 12:37:44 am
content: Quote from: pulsed_power on July 19, 2023, 12:32:23 amPhoto Q3 & Q4How do you create the replies with the text and collage?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 12:50:12 am
content: Quote from: pulsed_power on July 19, 2023, 12:37:44 amQ1, 2, 3, 4

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 19, 2023, 12:51:33 am
content: Quote from: pulsed_power on July 19, 2023, 12:37:44 amI just use Microsoft "Paint" that comes with Windows. You can use any image or Graphics editor for this kind of thing, but MS paint is pretty simple and basic.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 12:55:32 am
content: Quote from: pulsed_power on July 19, 2023, 12:50:12 amThank you for your assistance

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 19, 2023, 02:04:13 am
content: Quote from: pulsed_power on July 19, 2023, 01:32:28 amYou must have missed my reply above:I just use Microsoft "Paint" that comes with Windows. You can use any image or Graphics editor for this kind of thing, but MS paint is pretty simple and basic.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 02:12:03 am
content: Quote from: Kim Christensen on July 19, 2023, 02:04:13 amYou must have a different version. I am not able to get Paint to do any of that. Maybe you can send me your file and I can pick it apart to see how you did this?

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 19, 2023, 02:28:31 am
content: I'm running Windows 10... Paint has been the same for quite a few Windows versions. I think the Windows 11 version of Paint is basically the same but fancier looking.Thefile I already postedis one of the file formats Paint saves in. Paint just saves things as graphics in a few different formats (PNG, JPG, BMP, etc) so you can't really see how I did it. There are much better editors out there, but I just use Paint because I'm familiar with it. (Some things do frustrate me with Paint though, but it's simplicity is what keeps me using it)

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 02:33:00 am
content: Education and experience with SMD devices, tools required:1. One million watt work light2. Telescope that can see a Nats ass on the Moon3. One bottle of Valium

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 11:06:29 am
content: Attempt at PaintNow if I could collage I could compare the photos side by side

author: mikerj
author_rank: Super Contributor
timestamp: July 19, 2023, 11:46:59 am
content: Quote from: pulsed_power on July 19, 2023, 11:06:29 amJust resize the canvas. There are three little white squares, one on the lower edge, one on the right hand edge and one on the lower right corner. Hover over them with the mouse pointer and the pointer will turn into an arrow shape. Click and drag to resize the canvas. Give yourself enough area to paste in your additional images, at the end you can resize the canvas back to the final size required.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 12:06:19 pm
content: Quote from: mikerj on July 19, 2023, 11:46:59 amI am running Win 11 and my Paint menu is different, what version do you run?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 12:14:11 pm
content: Got i!I have been a constant user of AutoCad since 1985 with it's tool box, this Paint has little to no tool box.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 12:32:33 pm
content: I have found myself in constant need to learn additional software to make my daily task easier. They all seem overwhelming and I would rather contract the projects out as the need arises. Trying to find people available with this knowledge has become like finding a needle in a haystack.1. Photoshop2. Soid Works3. KiCad

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 03:37:59 pm
content: Please review and let me know if you think I have this correct

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 19, 2023, 03:45:52 pm
content: I got fooled by the European style transistors. (Just looked back in the thread. Are you using BC547 & BC557?)I assumed they were American style pinout.If they are BC547 & BC557, then they are flipped the wrong way by the looks of it. (Emitter and Collector swapped)

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 03:53:41 pm
content: 547& 557 are CBE

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 19, 2023, 03:59:01 pm
content: Well, then we can see from the above that Q3's collector is going to D1 which is wrong.Q4's collector is going to the T1 end of R1 when it should be Q4-emitter going there.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 04:10:16 pm
content: Quote from: Kim Christensen on July 19, 2023, 03:45:52 pmJust to double check

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 04:21:58 pm
content: Quote from: pulsed_power on July 19, 2023, 03:53:41 pmAFU! I will strip the #^$@ board and start again!

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 06:09:37 pm
content: Looking better?

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 19, 2023, 06:30:24 pm
content: Quote from: pulsed_power on July 19, 2023, 06:09:37 pmFrom what I can see, it looks OK.Not to get you to redo it again (Since this is just for a test) a little trick for reducing jumpers is to reorient the parts so the leads connect with less crossing of wires. Since I already drew it before I saw your rework (which is fine), here it is anyway:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 06:31:56 pm
content: Quote from: Kim Christensen on July 19, 2023, 06:30:24 pmYES that is much better

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 19, 2023, 07:07:31 pm
content: Quote from: Kim Christensen on July 19, 2023, 06:30:24 pmSince this is the first time I have worked with these perf boards I would be very interested in how you would lay the board out

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 19, 2023, 07:41:14 pm
content: I'd probably do something like this with no jumpers on the topside since it's simple enough. Run the G wire under the gap that D2 bridges. Squiggles by transistors are to avoid the CBE labels. Wiring would be straight in reality. The diode and R1 network I'd lay out in exactly the same orientation as in the schematic. Years ago I'd quickly do this in pencil on graph paper with each graph line cross being a board hole:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 02:39:11 pm
content: Quote from: Kim Christensen on July 19, 2023, 07:41:14 pmWith any luck I think I have it! Please review

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 02:51:08 pm
content: Additional photo

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 03:18:32 pm
content: See if this post works

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 20, 2023, 03:34:19 pm
content: Ok.. I noticed a few things:EDIT: Ignore the bit about the wire going left at the yellow "?". I see now that it's connecting to the cathode of D5.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 05:45:24 pm
content: I am unsure how visible these are but I will give it a shot

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 06:17:39 pm
content: Larger

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 06:19:23 pm
content: 2

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 06:19:53 pm
content: 3

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 20, 2023, 06:27:46 pm
content: What does this test setup look like on the scope?You may have to increase the sig gen level a bit more if it doesn't trigger.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 07:17:15 pm
content: Quote from: Kim Christensen on July 20, 2023, 06:27:46 pmsee attached

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 07:18:08 pm
content: Quote from: pulsed_power on July 20, 2023, 07:17:15 pminput

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 20, 2023, 08:18:08 pm
content: Post the updated top and bottom view of your perf-board again.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 08:40:17 pm
content: Quote from: Kim Christensen on July 20, 2023, 08:18:08 pmsee below

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 10:41:45 pm
content: Scope

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 10:57:00 pm
content: Test points 5 & 6

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 20, 2023, 11:13:22 pm
content: KimI just looked at your location. OMG! You live in one of the most beautiful places on Earth! Vancouver Island is very special to me.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 12:36:46 am
content: After send you these scope photos I now believe I recall you telling me that they are not relevantMaybe these will be of some value

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 02:10:18 am
content: Quote from: Kim Christensen on July 20, 2023, 06:27:46 pmThe signal gen is running at maximum which is 24vpp

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 21, 2023, 04:03:10 am
content: I think a lot of the problem is bad soldering. Here are some of the worst ones I could see, but you might want to add some flux and reflow all the joints:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 02:34:55 pm
content: Maybe?

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 21, 2023, 03:00:32 pm
content: That looks better. Don't forget to connect the center G pin to the rest of the circuit.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 03:28:48 pm
content: Houston we have ignition!

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 03:36:17 pm
content: Quote from: pulsed_power on July 21, 2023, 03:28:48 pmPhotos

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 21, 2023, 03:48:45 pm
content: So it works in the M70 now?Audiophiles will want to know if the discrete version sounds different than the blue module...

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 03:49:39 pm
content: Quote from: Kim Christensen on July 21, 2023, 03:48:45 pmin regard to the Audiophiles

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 03:50:25 pm
content: Quote from: Kim Christensen on July 21, 2023, 03:48:45 pmYes it works in the M70!

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 03:53:18 pm
content: Quote from: pulsed_power on July 21, 2023, 03:50:25 pmStep 1: BreadboardStep 2: Perf boardStep 3: How to create new IG PCB?

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 21, 2023, 04:43:14 pm
content: Quote from: pulsed_power on July 21, 2023, 03:53:18 pmYup. The PCB you already have should work if you changed the 3 resistors from 4.7K to 8.2K and the offending transistor pair was rotated. What program was it created in? Do you have those files?Having never played around with KiCad before, all this talk of PCB making got me to trying it out a couple of days ago. After watching this22 minute YouTube tutorial, I made a through-hole version of your board. It probably has some issues with sizing, but it was easier than I thought. There was a few minor differences from the video since the tutorial was for v5.99 and I was using v7.0.6 but still easy enough to follow the simple tutorial.Anyways, here's a teaser screen shot:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 04:54:22 pm
content: Quote from: Kim Christensen on July 21, 2023, 04:43:14 pmI have made a search to locate someone who can modify the existing PCB's and the price is beyond insane.I don't have the files, thinking it was done on KiCadThe previous boards are 18mm x 12mm

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 04:58:23 pm
content: Quote from: pulsed_power on July 21, 2023, 04:54:22 pmI certainly like the use of discrete components (user friendly)

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 05:09:01 pm
content: Dimensions

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 21, 2023, 05:17:29 pm
content: Should be easy enough to recreate your SMD version in KiCad. I don't mind trying to do that part. No guarantees, but I'd send you the files so you have them.My TH PCB could definitely be made a bit more compact by moving the parts around a bit. Or a SMD version using larger SMD parts, like 0805 or 1206 resistors, etc, if you wanted it small but not too hard to service.Not sure about how to order a populated PCB from a place like jlcpcb, since I've never done it myself, so you'd be on your own for the actual upload/ordering part.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 05:31:30 pm
content: Quote from: Kim Christensen on July 21, 2023, 05:17:29 pmMore dimensions

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 05:34:14 pm
content: Not sure about how to order a populated PCB from a place like jlcpcb, since I've never done it myself, so you'd be on your own for the actual upload/ordering part.No problem

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 05:36:40 pm
content: My TH PCB could definitely be made a bit more compact by moving the parts around a bit. Or a SMD version using larger SMD parts, like 0805 or 1206 resistors, etc, if you wanted it small but not too hard to service.Since you have been so kind in all this I don't want to push it more than I already have. I would like to see both larger SMD and Discrete

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 21, 2023, 08:19:06 pm
content: I see now why they used such tiny SMD parts for that PCB. They were trying to make it the same size as the original. Possibly it could be taller and a bit wider.How much clearance is there above itwhen the M70 is completely assembled? ie: Is there another PCB mounted above with components that stick down into that space? Could you actually assemble the M70 with that perf-board you made without it touching anything else and shorting out?A through-hole PCB would be taller and/or asymmetrical (Not as aesthetically pleasing) than the original:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 11:03:33 pm
content: Size

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 21, 2023, 11:09:01 pm
content: Size 2Nothing above to interfere

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 22, 2023, 02:17:56 pm
content: I see now why they used such tiny SMD parts for that PCB. They were trying to make it the same size as the original.Possibly it could be taller and a bit wider.YESHow much clearance is there above it when the M70 is completely assembled? ie: Is there another PCB mounted above with components that stick down into that space?NOCould you actually assemble the M70 with that perf-board you made without it touching anything else and shorting out?YESA through-hole PCB would be taller and/or asymmetrical (Not as aesthetically pleasing) than the original:NO PROBLEM TO EXTEND AS YOU HAVE SHOWNMy one concern with the size is that I am working with just one of the Yamaha units that use this device, the other units may not have the same space available.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 22, 2023, 02:40:42 pm
content: Yamaha B6

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 22, 2023, 04:38:07 pm
content: Yamaha A760 & A960

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 22, 2023, 04:39:02 pm
content: A760

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 22, 2023, 04:41:21 pm
content: To the best of my knowledge the only Yamaha M70, B6, A960 and A760 use the IG04080

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 22, 2023, 05:18:09 pm
content: More messing around with KiCad last night. Played around with the Thru-hole and a small SMD version. Getting there slowly:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 22, 2023, 05:54:10 pm
content: Quote from: Kim Christensen on July 22, 2023, 05:18:09 pmLooks very good 👍

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 24, 2023, 12:12:27 am
content: Did you have a chance to work on design?

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 24, 2023, 03:20:08 am
content: Mostly I was trying to figure out which files to export from KiCad to order assembled PCBs from JLCPCB. Then I went down the "part rotation rabbit hole" and other issues with FABs. Ended up adding an extension to KiCad to deal with the way JLCPCB wants the Pick & Place and BOM files formatted, and to access their parts database directly from KiCad, rather than doing it manually. Also learned that they tend to follow the silk-screen when there is an error in the placement file. This probably explains how Jason's PCB ended up with a rotated part, since he had no silkscreen orientation marks for the parts so there was no way for the production crew to catch the error.Anyway, I did make a shorter version of the SMD PCB. I assume you'll still be using those 90deg header pins to mount it. There's a bit extra PCB on the bottom to account for the spacing make by the black plastic on the pin.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 24, 2023, 03:29:13 pm
content: I used this black spacer for the PCB that I built because of needed clearance to the parts close too T1

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 24, 2023, 08:32:55 pm
content: Quote from: Kim Christensen on July 24, 2023, 03:20:08 amDo you feel like it is ready to submit for production?

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 24, 2023, 09:20:23 pm
content: It might need a few tweaks. We could trim a bit off the bottom of the PCB so it'll fit better (Over D506, etc) in the other amplifiers (A760 & A960). The reason I made the PCB a bit longer below the header mounting holes was for better mechanical support against the M70 board. (See drawing attached)Anyways. Did a test upload to JLCPCB to see how the process worked and whether it would accept my files. There were a few glitches at first but in the end it seemed to work OK. Got some internal server error on the site. Another time while processing my files I got spinning wheel until I refreshed it. Once it borked on CPL file upload, etc.Again there are issues with the parts rotation as displayed in their previewer. I have it correct according to their FAQ, but still the transistor pairs appear improperly rotated. I can fix it on their website, but then I've seen comments on the forums saying their previewer can't always be trusted. BUT, the comment is that they'll check our silkscreen to make sure it's correct which is why I added it. Here's a collage of of the process:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 24, 2023, 10:09:35 pm
content: I just sent you a PM

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 24, 2023, 11:41:30 pm
content: Ah... Figured it out. You can get the same part on different reels which are oriented differently so the rotation will change depending on what reel type the FAB is using.So this explains a lot of these problems people are having. So I checked the details of the parts that JLCPCB / LCSC are using, figured out the reel type, and yes, the rotation given by my KiCad plug-in was wrong:

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 25, 2023, 04:07:13 pm
content: Quote from: Kim Christensen on July 24, 2023, 11:41:30 pmI am sure it would have taken me a decade to determine that!

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 25, 2023, 07:02:08 pm
content: So, do you want me to leave the board as is or trim the bottom off a bit? Another option for the A760 & A960 users is for them to use longer header pins so it clears those extra components which are not as close on the M70.Quote from: Kim Christensen on July 24, 2023, 09:20:23 pmSee render below (Ignore ugly silkscreen for header pins)

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 26, 2023, 01:27:16 am
content: leave the board as is

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 26, 2023, 01:45:58 am
content: Should you recall when Jason had that first run produced JLCPCB built them six boards on a slab and five slabs for a total of thirty. When I asked him about that he claimed he had no idea or knowledge of that.He claimed he ordered 5 boards and only 2 of them were loaded with parts.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 26, 2023, 02:30:39 am
content: So he ordered 30 boards, had them shipped to his address, and then sent 2 of them them to you?The minimum order at JLCPCB is 5 boards which is what you saw on my screen shots.I did not panelize my PCB as Jason did, since JLCPCBkind of says on their sitethat it won't be cheaper if you do. Perhaps I'm misreading this, but it sure sounds like that.ie: They'll see what you're doing and will charge you per PCB anyway.They did have an option for JLCPCB topanelize them for you, but you need to order enough PCBs so the panel is over a certain size to fit their V-cut machine. So I just did the trial quote without panelizing as I didn't see any advantage.

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 26, 2023, 04:11:33 am
content: Quote from: pulsed_power on July 26, 2023, 01:27:16 amOK, here's the finished board files. You can check it out in KiCad, or just upload* the files in the "production_files" folder (Starting with the Gerber zip file)to JLCPCBafter creating an account and logging in.Note: No need to unzip the "GERBER-IG04080-SMD.ZIP" file itself. Just upload it.* Maybe don't upload to JLCPCB until you are ready to order. The price seems to go up every time you look. (Maybe by uploading you are using a new user discount coupon or something)EDIT: If you only upload the "GERBER-IG04080-SMD.ZIP" file, you'll get a blank PCB. You'll also need to tick the switch/box on the website for PCB assembly after uploading the gerbers, choosing board color, quantity, etc. Then you'll get another page were you can upload the other two files ( BOM-IG04080-SMD.csv & CPL-IG04080-SMD.csv) which define the parts and their placement.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 26, 2023, 02:42:41 pm
content: So he ordered 30 boards, had them shipped to his address, and then sent 2 of them them to you?He order 5 pcb's to be shipped to me directly from JLCPCB. Then what I received from JLCPCB was 5 cards each containing 6 pcb's

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 27, 2023, 01:32:09 am
content: Is PCBWAY and JLCPCB the same company?Their websites are almost identical

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 27, 2023, 04:50:41 am
content: They seem to be different companies based in the same area according tothis article.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 27, 2023, 12:22:48 pm
content: Please review

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 27, 2023, 03:13:29 pm
content: BOM looks OK to me.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: July 28, 2023, 03:04:25 am
content: ? Please review

author: Kim Christensen
author_rank: Super Contributor
timestamp: July 28, 2023, 03:35:17 am
content: By "through holes" they mean the 90 deg header pins that go in T1, G, & T2. Probably best that you solder those on yourself. They've just noticed that those 3 holes are empty, and are double checking that's what you really want.The "SMT Pads" count of 9 seems a bit odd, but it probably means the total number of SMD parts (9) and not the total number of SMD pads. (29)The rest looks OK...

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 08, 2023, 12:53:01 am
content: Please review:Hi,Sorry for keeping you waiting.The boards for have been assembled and here’s the pictures for your confirmation.Pls pay attention to the component orientation and polarity.Looking forward to your soon comment to proceed, thanks.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 08, 2023, 02:21:00 am
content: From what I can see, it looks good. Next would be to test it with the sig gen and scope like we did with the breadboard version you'd made. If that's Ok, then try it in your working M70.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 16, 2023, 05:06:20 pm
content: Test result for NEW IG04080

author: Benta
author_rank: Super Contributor
timestamp: August 16, 2023, 10:02:28 pm
content: Looks great to me and very close to the original simulation. Trigger point is at around 8 V.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 18, 2023, 09:24:01 pm
content: Electrolytic BoardBR 3VACYE 2.8VACRE 4.8VACWH 4.5VAC+LB +14.4VDC-LB -14.3VDC-HB -23.4VDC-HB+HB +23.5VDC+HB+L +7.02VDC-L -6.8VDC+B +9.8VDC-B -9.4VDC

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 18, 2023, 09:43:12 pm
content: QuoteAs per our last e-mail, do the B+ and B- voltages, that you measured on the "Electrolytic Board", now make it over to the "CONTROL CIRCUIT (1)" PCB?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 18, 2023, 09:49:58 pm
content: D604 0.46V DROPD603 0.46V DROPR612 0.33V DROPD601 0.047V DROPR605 0.00V DROPR607 770MV DROPR606 0.1MV DROPTR601 E/B 43.1

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 18, 2023, 09:53:41 pm
content: B+ -15VDCB- -20VDC

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 18, 2023, 10:12:11 pm
content: Quote from: pulsed_power on August 18, 2023, 09:53:41 pmIs that actuallynegative15VDC as measured relative to "E"? It should be a positive voltage there.B+ and B- should be the same as on the "Electrolytic Board"

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 18, 2023, 10:17:02 pm
content: YES!!! I found the problem and now the AMP is ALIVE!!!!!!!

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 18, 2023, 10:23:15 pm
content: Congrats! So it's running with the new IG04080 as well?

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 18, 2023, 10:24:58 pm
content: YES!!!!! The old IG was dead and I believe between the bad IG and birds nest of frayed wires.

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 18, 2023, 10:29:21 pm
content: I was very worried about placing the new wires and EURO connectors that I could have created a major nightmare, but I pulled it off!!!!

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 18, 2023, 10:35:49 pm
content: Did I say Thank You at least 100 times? If not, I do Thank You at least 100 times!

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 18, 2023, 10:46:21 pm
content: Maybe I am cross-eyed!

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 18, 2023, 10:46:33 pm
content: You're very welcome. I think you did somewhere in this thread before, but I'll happily accept an additional 100 as well.It's nice to see things work out in the end.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 18, 2023, 10:51:29 pm
content: Quote from: pulsed_power on August 18, 2023, 10:46:21 pmWell, at least the problem there is pretty obvious.

author: Benta
author_rank: Super Contributor
timestamp: August 19, 2023, 12:06:48 am
content: Quote from: pulsed_power on August 18, 2023, 10:17:02 pm

author: pulsed_power
author_rank: Frequent Contributor
timestamp: August 19, 2023, 02:08:49 am
content: Will have to see if all survives final calibration: