hybridfree/eevblog-posts huggingface dataset:
Schematic for Sherwood AI-7010 - Page 1
Forum section: electronics / repair

author: Miwer
author_rank: Contributor
timestamp: November 14, 2016, 08:30:09 pm
content: Hi all,Does anybody have a service manual or schematic for the Sherwood AI-7010 amplifier?I have not been able to find anything besides dubious scans on various pay sites. I cannot find a free download anywhere. I have also checked the sites linked to in the sticky thread.Thank you.

author: SAUL BRITTO
author_rank: Frequent Contributor
timestamp: November 14, 2016, 09:52:35 pm
content: Quote from: Miwer on November 14, 2016, 08:30:09 pmhttp://www.ko4bb.com/getsimple/index.php?id=manualswww.elektrotanya.comhttp://bama.edebris.com/manuals/www.ebaman.com

author: nctnico
author_rank: Super Contributor
timestamp: November 14, 2016, 11:26:38 pm
content: AFAIK Sherwood is a brand from Bose. Maybe try there.

author: Neganur
author_rank: Unknown
timestamp: November 15, 2016, 10:33:09 am
content: Try Schtungsdienst Lange in Berlin:http://www.schaltungsdienst.de/anleitungen/katalog.htmlSearch for keyword AI7010I bough the schematics for my equalizer there some years ago.(You don't get everything for free always)
Fluke 5440B Warm-up - Page 1
Forum section: electronics / repair

author: wn1fju
author_rank: Frequent Contributor
timestamp: November 16, 2016, 05:58:23 pm
content: My friend and I both recently acquired Fluke 5440B calibrators. Mine is the straight "B" model and his is the "B/AF." On a cold start, mine starts out about 40 ppm low (at 10V) and stabilizes to 10V in 30 minutes. His starts out about 500 ppm low and stabilizes in about an hour. Why the difference? Anyone out there with a 5440B care to share their warm-up experience?

author: wn1fju
author_rank: Frequent Contributor
timestamp: November 16, 2016, 09:08:41 pm
content: Oops, never mind. Same question posted by my friend on the Metrology forum.
Siemens LOGO PLC repair - Page 1
Forum section: electronics / repair

author: CookieB
author_rank: Newbie
timestamp: September 22, 2015, 03:13:41 pm
content: Hy,I got a Siemens LOGO PLCIt failed in an industrial application and therefore simply got replaced. Normally they would throw it away but due to my interest in such devices I got my hands on it.It served as a display piece on my shelf for quite a while but recently I was thinking why not try to fix it.It pops open easily (without any tools) an inside there is are 3 PCB’s.A close inspection of all components shows only one that is physically damaged.It is a component on the back, of the biggest PCB so unfortunately there is no silk screen.The text on the component is small but I managed to read it and it has a Motorola symbol followed by “837B” and “ZP621” on the second line.Googling this seems to learn me it is a Zener diode.I’m not very experienced with electronics so that’s why I’m here.What is the chance of this being the sole problem and what Zener diode can I replace this one with (I can’t find that one for sale anywhere). Any advice for where to get it is welcome to (I live in Belgium).Here are some Pictures:https://www.dropbox.com/sh/xpk0zbabswhoa21/AACP053EqfEPnzvUnqVVaqz_a?dl=0

author: singapol
author_rank: Frequent Contributor
timestamp: September 22, 2015, 05:32:30 pm
content: Most probably 1N837...not a zener but a switching diode. The close equivalent is 1N3070 or NTE177.http://www.farnell.com/datasheets/46802.pdf

author: PTR_1275
author_rank: Frequent Contributor
timestamp: September 23, 2015, 04:52:19 am
content: I just grabbed one of the logos from our storeroom and it is different internally. We use the 12/24v ones not 240v. I can't see a similar component on ours to even confirm the part number for you.

author: bruno_0021
author_rank: Newbie
timestamp: November 13, 2016, 03:12:24 pm
content: Hello CookieBI have exactly the same problem and I think ZP621 is not a switching diode but a Zener. Do you have found a good diode ?If yes, can you tell me the reference of your new diode please ?Bruno.

author: kmike
author_rank: Regular Contributor
timestamp: November 14, 2016, 01:37:02 pm
content: Hi,I disassembled one of the oldest working LOGOs that I have here, but it is completely different (0BA3).That LOGO You have there is one of the first ones (0BA0 at the end of the order number), I would not recommend spendig too much time on it, because the old ones have a very limited memory and very few functions to work with. Also the output relays are likely to be defective at that age, although this depends on the switching count, so I would not rely on those either.edit:oops, sorry to have replied to this old thread, did not read the date...br,mike
HP 3325B schematic request - Page 1
Forum section: electronics / repair

author: vindoline
author_rank: Unknown
timestamp: November 06, 2016, 04:40:12 pm
content: Hi, I've picked up an HP 3325B function gen that has some issues. I've found several copies of the service manual online, but all them have low-res scans of the schematics and layout diagrams. Does anyone have a nice, hi-resolution scan of the schematic diagrams and board layouts for this model? It would be very much appreciated. Thanks.

author: pinyoro
author_rank: Contributor
timestamp: November 06, 2016, 05:18:49 pm
content: Hi. Someone scanned some high resolution ones and uploaded them. Have you done a search?

author: Tony_G
author_rank: Super Contributor
timestamp: November 06, 2016, 05:22:21 pm
content: Dave from Artek Manuals will sell you a great scan of all 3 3325B manuals for US$7.50 -http://artekmanuals.com/manuals/hp-manuals/.Tons of other manuals as well - All officially licensed from HP/Agilent/Keysight/Etc - Great service, great source.TonyG

author: Lorenzo_1
author_rank: Regular Contributor
timestamp: November 06, 2016, 10:53:04 pm
content: There's hi-res schematics of 3325a version on KO4BB website. May be of some use.

author: vindoline
author_rank: Unknown
timestamp: November 07, 2016, 12:55:31 pm
content: Thank s for the suggestions! Of course I did a search first. All the schematics I found were low res. The KO4BB looks great, though it's the 3325A model. I don't think there's much difference between the A and B models. It's also great to know about the Artek manuals site. The cost sounds very reasonable!

author: dacman
author_rank: Frequent Contributor
timestamp: November 07, 2016, 11:10:53 pm
content: I think one difference is that the 3325A has hard plastic pushbuttons where the 3325B has soft pushbuttons.

author: vindoline
author_rank: Unknown
timestamp: November 09, 2016, 01:38:58 pm
content: Quote from: Tony_G on November 06, 2016, 05:22:21 pmI just wanted to follow up that I went ahead and got the professionally scanned manual set from Artek. The quality is very good. Definitely worth the modest cost for the high resolution graphics and the searchable text!

author: Tony_G
author_rank: Super Contributor
timestamp: November 12, 2016, 03:19:46 pm
content: Good to hear. I've bought a lot of manuals from Artek for the same reasons you state. Glad your happy with them.Good luck on the 3325B, I'm still trying to fix mine (fails 3rd harmonic 100Hz performance test).TonyG

author: vindoline
author_rank: Unknown
timestamp: November 14, 2016, 03:49:13 am
content: Thanks for the good wishes. Unfortunately, my unit has some less subtle issues...
Spectrum Analyzer Agilent E4408B - Worth buying for Repair? - Page 1
Forum section: electronics / repair

author: SaabFAN
author_rank: Frequent Contributor
timestamp: November 07, 2016, 08:53:23 pm
content: I found a Agilent E4408B online that doesn't respond to signals anymore, but otherwise seems to be working - At least there are no error-messages.I'm guessing that the 1st Mixer is damaged and doesn't work anymore.Does anyone know if the Mixer in these devices is actually repairable or can be replaced by something from minicircuits?I don't need the full bandwidth up to 26GHz. The lower band up to 3GHz or so would be enough for the time being.What else could have died?On the pictures it looks like the noise-level increases with frequency - So the attenuator is definitely also a suspect.

author: SaabFAN
author_rank: Frequent Contributor
timestamp: November 11, 2016, 09:25:56 pm
content: Has anyone taken a look at the Mixer of these devices?Unfortunately, I haven't found anything on the web so far.How vulnerable are these Mixers btw. and are there any other known failure points?

author: ap
author_rank: Frequent Contributor
timestamp: November 12, 2016, 06:19:07 am
content: The problem with these is that the special parts, if failed, are extremely expensive. There are quite a few of them with no replacement other than original. Even used, if you get one, they are expensive. Also, there are a couple of metal-enclosed PCBs, at least one of which is very hard to access internally and mesaure (plus, they also have several custom parts; you cannot even buy them from keysight). So its a major gamble. Older Agilent analyzers (8562 or 8563 e.g.) are easier to repair because much more used spare parts are available at reasonable prices. Plus, you have to have the right test gear to do the measurements (no chance if you don't)

author: SaabFAN
author_rank: Frequent Contributor
timestamp: November 12, 2016, 10:32:04 am
content: Ok, that's not so good, I also noted the seller has put up some new pictures with the following messages on screen:"System Alignment - Align Nov. All required""LO Unlock""LO Unlevel"Seems to me at least to be a similar error that was once shown and fixed on the "The Signal Path"-Channel on Youtube. So there might be hope that it is fixable without buying some expensive replacement parts.Edit: Further research suggests that this failure is due to an error during construction of the ESA-E and ESA-L Series that was corrected sometime during the production cycle of the instruments.There's a service bulletin available that deals with this exact problem.

author: ap
author_rank: Frequent Contributor
timestamp: November 13, 2016, 11:32:35 am
content: These had problems, several, but I did not find this one. The LO path has so many custom parts that I still think one would have to be very very lucky to fix it.

author: SaabFAN
author_rank: Frequent Contributor
timestamp: November 13, 2016, 08:12:47 pm
content: Well, good luck to the winner of the auction then, who paid over 1700€Hint: Wasn't me^^
How to repair a FeelTech FY3200S waveform generator? - Page 1
Forum section: electronics / repair

author: EnricoTanz
author_rank: Newbie
timestamp: November 12, 2016, 12:50:23 pm
content: Hi all, im a new user! I've been following this forum for some months, looking for a good oscilloscope. I've found itI also bought a FeelTech FY3200S waveform generator, it was very cheap, and it came from China.It worked fine, until i connected it to my pc.I installed the drivers and the softwares properly, following the instructions on its cd.Suddenly, as last step, i connected it to my pc via usb, and i turned it on and...It stopped working! The software can't find it, and it always shows black squares in its display. Also when i disconnect it from my pc.I think it's gone, but hopes are always alive.The seller sent me a refund, but I don't need to ship it back, so.. I don't want to throw it in the trash...I've looked everywhere for a ''factory restart'' keys combination, but I found nothing.Do you have any idea?Thank you....And sorry for the bad english

author: TheoB
author_rank: Regular Contributor
timestamp: November 13, 2016, 06:19:02 pm
content: Open it up and measure the power supplies. Check the crystal oscillator. Since it worked for a while it could also be a bad solder joint or connector. The basic fault finding proceduresYou might also have killed it when you connected the USB cable to your PC while powered on. The signal generator is known to have a large powersupply leakage when you don't ground it first.
Repairing a dead GTX 660Ti, need advice - Page 1
Forum section: electronics / repair

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: November 13, 2016, 02:16:57 am
content: I've bought a GTX 660Ti PCB off of ebay, listed as not working.I've strapped a cooler onto it, and put it in an asrock motherboard as a secondary GPU.The bios' system browser doesn't even detect anything in the pcie slot, and nvflash detects nothing.I desoldered the bios chip, dumped it, and flashed a new bios from techpowerup's bios collection, one for the original card.Put it back in, still the same result. I've checked the 0 ohm resistors/fuses, all are intactWhat should I try next? None of the VRMs look visibly exploded...

author: TiN
author_rank: Super Contributor
timestamp: November 13, 2016, 03:19:25 am
content: Measure voltage on GPU, memory, aux rails?

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: November 13, 2016, 04:16:17 am
content: Quote from: TiN on November 13, 2016, 03:19:25 amHow could I forget the number one rule? Thou shall check voltages!

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: November 13, 2016, 04:38:44 am
content: Vcore 0.939Vmem 1.605These seem reasonable for an idle gpu.
Help! HP 6434b DC Power Supply problem - Page 1
Forum section: electronics / repair

author: itsmerandy
author_rank: Newbie
timestamp: November 13, 2016, 01:06:13 am
content: Hello I am trying to get my Power supply working and apparently don't have the knowledge to figure it out. Anyways its an HP 6434b DC Power supply and the problem is that it won't adjust to the settings I need. For example - if I set Voltage to 15 vdc I can't get amperage above 10 amps or vice versa. its like it wants to keep the meters similar in voltage and amperage. If I need 25 amps I have to crank the voltage up to 40 vdc. This is using a dummy load 1.6 ohm's. If I use a 10 ohm load I can't get amperage over 10 amps and voltage is around 10 vdc as well. I have gone over this circuit board many times testing components and everything test like its should. I have downloaded the service manual as it is readily available online for download and followed diagnostics with no luck. PLEASE HELP!!!! I have spent hours trying to resolve this! Just need a circuit guru to help me.Thanks!

author: VK5RC
author_rank: Unknown
timestamp: November 13, 2016, 01:22:21 am
content: Remember the current is related to the voltage divided by the resistance, 40v/1.6ohms is about 25A. The 40A will require a load less than 1ohm at 25V.The current knob sets the limit to which the current will go, not the actual current. The voltage is the main parameter set, the current can, if the load is low enough resistance, go up to the limit set, then the supply will drop the voltage to keep the current under the set current limit.

author: itsmerandy
author_rank: Newbie
timestamp: November 13, 2016, 04:06:36 am
content: Quote from: VK5RC on November 13, 2016, 01:22:21 amI think I'm just use to the digital power supplies I have and you just set them for what you want. No wonder I couldn't find any bad components.Thank you!

author: Monkeh
author_rank: Super Contributor
timestamp: November 13, 2016, 04:37:00 am
content: Quote from: itsmerandy on November 13, 2016, 04:06:36 amI think you just need to learn and understand Ohm's law.
Hameg HM507 / 404-2 or 407 calibration instructions  - Page 1
Forum section: electronics / repair

author: DeanKindleysides
author_rank: Contributor
timestamp: November 12, 2016, 08:36:56 pm
content: Hameg HM507 / 404-2 or 407 calibration instructionsNeeded thanks in advance nothing on Hameg site

author: tautech
author_rank: Super Contributor
timestamp: November 12, 2016, 08:53:41 pm
content: Google can help, try these:http://www.ebaman.com/index.php/remository/ELECTRONICS/Test-Equipment/HAMEG/Scopes/https://docs.google.com/document/d/1Nz4eIV5vqbVZMmxHI6kut_WGkiRt8AfmOIVY3CbopX4/edit
Recabling headphones question - Page 1
Forum section: electronics / repair

author: admiral_akmir
author_rank: Newbie
timestamp: November 14, 2016, 03:18:20 pm
content: I've got a pair of DT770 pro and DT880 pro, and I'd like to recable both. I've looked up blog posts of people who have done this before, and I have some questions.1) In one of the writeups, there was a warning not to overheat the terminals when desoldering the wires from the driver, or the driver could be destroyed. I'm wondering how big of a risk this is, as I've only seen mention of it once. There are a number of mod tutorials for those specific headphones, but none of the others seem to mention this risk when talking about soldering.2) On a brief writeup on a different mod for a different pair of headphones, the required items included lead free solder. So far, all of the tutorials I've watched on soldering have been for PCB's, and either 60/40 or 63/37 were recommended. Is there some kind of special requirement when working with the connections in headphones or sound systems in general? Why lead free? They gave no explanation for this.

author: Lightages
author_rank: Unknown
timestamp: November 14, 2016, 08:20:10 pm
content: If you aren't experienced at soldering, then you need to practice first on other things that you don''t care about. Dave has done some videos on soldering. The type of soldering you need to think about is reflow soldering where you pre-tin both parts to be soldered and then join them with a bit of heat.DO NOT USE lead free. Use normal solder as its melting point is lower and is is easier to get a good joint with lower heat.

author: admiral_akmir
author_rank: Newbie
timestamp: November 14, 2016, 08:56:31 pm
content: Quote from: Lightages on November 14, 2016, 08:20:10 pmI've got a couple of very low end Biostar boards that both started having various blue screens and failures within the same year. Looked at them, and they both have bad capacitors, so I was going to start by recapping those.I looked up reflow soldering, and pre tinning, and they seem like two separate things? All of the reflow stuff I've looked at involves solder paste and reflow ovens or heat pencils. I'm assuming you meant just to pre tin both like you said, and then quickly join them to form the joint, as opposed to holding the iron to the terminal, heating it up and letting the hot terminal melt the solder?

author: Lightages
author_rank: Unknown
timestamp: November 14, 2016, 09:10:50 pm
content: Reflow is a bad term on my part. Pre-tinning and then reheating (formerly reflowing) the parts together causes the least amount of heat soaking and damage.

author: admiral_akmir
author_rank: Newbie
timestamp: November 14, 2016, 09:11:38 pm
content: Quote from: Lightages on November 14, 2016, 09:10:50 pmGreat, thanks for the tips.

author: Rasz
author_rank: Super Contributor
timestamp: November 15, 2016, 08:47:32 am
content: Quote from: admiral_akmir on November 14, 2016, 08:56:31 pmagain:Quote from: Lightages on November 14, 2016, 08:20:10 pm
Keithley 2015 Front/Rear Terminal Switch Replacement - Page 1
Forum section: electronics / repair

author: madsci
author_rank: Regular Contributor
timestamp: November 11, 2016, 09:35:18 pm
content: The terminal switch on my Keithley 2015 has sprung and thus has unfortunately turned itself into a momentary switch.Does anyone have an idea of what kind of switch is used and where I could get a replacement? I'm guessing its a 4PDT type but the number of pins suggest it may be more complex internally.

author: wn1fju
author_rank: Frequent Contributor
timestamp: November 11, 2016, 10:08:28 pm
content: It is a 6PDT switch. I did the replacement a couple of months ago. If I remember correctly, I used Mouser 611-SF6UEE. The only problem I had was that the switch body was about 1 mm longer than the original one and it hit the component at the rear of the switch. But it was easy to bend the leads of the component and move it a bit.

author: madsci
author_rank: Regular Contributor
timestamp: November 12, 2016, 07:41:05 am
content: Thanks so much for the part number!Bonus: Mouser is so close by my location that ground shipments get to me overnight. (or I can just call it in and pick it up if I'm really in a bind.)
Hakko FX-951 Errors - Page 1
Forum section: electronics / repair

author: cmccul002
author_rank: Newbie
timestamp: November 13, 2016, 04:31:04 am
content: Greetings,I have a Hakko Fx-951 thats started throwing S - E errors.I followed troubleshooting, and the manual says its an issue with the hand iron basically, but I have tried 2 other known good FM-2027 irons. Same issue.I cant find any schematics for the 951 or any troubleshooting for this type of issue.

author: chihaxinh
author_rank: Regular Contributor
timestamp: November 13, 2016, 06:24:14 am
content: Hakko 951 using lm358 for reading sensor value ! You can check lm358 good or bad

author: nanofrog
author_rank: Super Contributor
timestamp: November 13, 2016, 02:17:29 pm
content: Have you tried contacting Hakko USA?

author: cmccul002
author_rank: Newbie
timestamp: November 13, 2016, 03:17:53 pm
content: Quote from: nanofrog on November 13, 2016, 02:17:29 pmNo I bought it used, but worked up until now.

author: JacobPilsen
author_rank: Regular Contributor
timestamp: November 13, 2016, 04:49:52 pm
content: Quote from: cmccul002 on November 13, 2016, 04:31:04 amMe too.Could You please take some hi-res pictures of it's PCB

author: riyadh144
author_rank: Unknown
timestamp: November 13, 2016, 05:43:36 pm
content: I had the same problem with FX888, mine was fake.

author: cmccul002
author_rank: Newbie
timestamp: November 13, 2016, 08:07:07 pm
content: Heres some pics

author: nanofrog
author_rank: Super Contributor
timestamp: November 14, 2016, 02:40:05 pm
content: Quote from: cmccul002 on November 13, 2016, 03:17:53 pmI'd still recommend you contact them as they've been helpful to others in the past IIRC, particularly as they don't actively publish their schematics.Can't hurt at any rate.

author: cmccul002
author_rank: Newbie
timestamp: November 16, 2016, 03:55:35 am
content: Quote from: chihaxinh on November 13, 2016, 06:24:14 ameHow would one go about testing the lm358?

author: chihaxinh
author_rank: Regular Contributor
timestamp: November 16, 2016, 04:03:40 am
content: You can replace , it's cheap ! Or pls check voltage output of lm358 !Sent from my ASUS_X008D using Tapatalk
Sony HCD-SHAKE5 - power supply schematic - Page 1
Forum section: electronics / repair

author: cbarbos2
author_rank: Newbie
timestamp: November 08, 2016, 12:13:15 pm
content: Hello, guys.Does anybody have the schematic of the power supply for the HCD-SHAKE5, Sony Home Audio System?I got the service manual using Google but in it there is no power supply schematic.Thanks a lot for any help.Carlos
PLX Luxor flashlight - Page 1
Forum section: electronics / repair

author: samverstraete
author_rank: Newbie
timestamp: November 07, 2016, 08:18:02 pm
content: Hi, this is for all the owners of a PLX Luxor flashlight. You might run into the same issue I ran across, because, in my opinion, this is a design flaw.I love my Luxor flashlight. It has everything I want: firm grip, bright when needed too, but dimmable to last longer, big LiPo battery, focus adjustable to almost 360°, display that has all the info, … So I was very unhappy when it didn’t work anymore and decided to try and fix it.At one point I noticed my flashlight was turned on. I couldn’t turn it off anymore and when I reconnected the battery it turned on, but the buttons didn’t work. Reconnecting the battery resulted in the flashlight sometimes doing nothing at all or turning on but not reacting to any buttons (not even turning off).I played around with it a bit and then noticed when I pressed the function button while reconnected the battery, ‘locked’ would show up on the screen. In a normal situation you can lock the flashlight by simultaneously pressing the power button and the function button. So that means that the power button somehow was stuck. I opened up the flashlight.One tip: unscrew all screws, also the ones near the buttons, the main pcb and button pcb come out to the button-side, the plastic holder to the other side. I only figured that out when I removed the main pcb to the other side, bending over all the buttons while doing it.The power button circuit is pretty easy. Basically it is an pull-down circuit using R13 on the high side and the button on the low side connected to GND. It looks like the trigger is connected on two places to the microcontroller.And by the way: scraping off the partnumbers on the IC’s… common guys, that’s just silly.The repair:So… There’s 2.7V at one side of R13, that seems to be the supply voltage and 1V at the other side. R13 measured a bit shy of 10k so 0.1mA is going through it. Now 1V that’s really on the edge and it’s bad practice the use that voltage to trigger something. Either somehow my micro is consuming too much or R13 is a bit too high. So I decided to solder another 10k on top of it, making it 5k. And magically the power button and thus the flashlight worked again as before.
levell tg303 signal generator service manual repair - Page 1
Forum section: electronics / repair

author: matt09
author_rank: Regular Contributor
timestamp: November 04, 2016, 02:35:54 am
content: Hi all,Struggling to find info on this generator for a repair. Can anyone advise?Thanks

author: singapol
author_rank: Frequent Contributor
timestamp: November 04, 2016, 03:40:43 am
content: What seems to be the problem?

author: matt09
author_rank: Regular Contributor
timestamp: November 04, 2016, 11:50:18 am
content: As I was using it control pot to change frequency simply stopped working. Oscillator etc is all fine just that the frequency for each range is locked.

author: singapol
author_rank: Frequent Contributor
timestamp: November 04, 2016, 01:44:52 pm
content: Quite possible that control pot is broken or wire connection broken which should be easy to fix. BTW this is ageneric type of RC function generator so not to worry.

author: matt09
author_rank: Regular Contributor
timestamp: November 05, 2016, 02:06:46 am
content: Obviously I have checked those. There's a fair few devices inside so a schematic would make things MUCH easier. Does anyone know anything about the company Levell? Haven't been able to find much.

author: singapol
author_rank: Frequent Contributor
timestamp: November 05, 2016, 03:26:04 am
content: Quote from: matt09 on November 05, 2016, 02:06:46 amBy your reply it seems you are knowlwedgeable about such things. Schmatics are hard to come by online as companies want to protect their IP but they must have inspiration from somewhere first?Please answer a few questions, Is TG303 mircroprocessor controlled as everyone knows one can make a software function generator plus the frequency counter? If it is fully a discrete design does it use opamps , transistors,resistors,capacitors and diodes to first generate a triangle wave then convert to square wave and then massage to a sine wave to finally to an amplifying stage? Does it have opamps like LM741,LM308, FET transistor, CA3086 transistor array, frequency counter ic, 2N2905 and 2N2904 medium power output ? Or does it use a ICL8038 or MAX038 ic function generator ?

author: matt09
author_rank: Regular Contributor
timestamp: November 07, 2016, 06:43:07 pm
content: Yeah this place is great for schematics so was hoping someone might have something..It's pretty old so all old school kit in there, CA3086 and opamps.Think it could be rip off of this but the board inside is quite different and the frequency control doesn't match the schematic.https://alexkaltsas.files.wordpress.com/2012/07/voltcraft_fg1617.pdf

author: matt09
author_rank: Regular Contributor
timestamp: November 07, 2016, 07:49:51 pm
content: Fixed now, it was an opamp gone bad. Nightmare tracing it out without a schematic though.
TDS 7xx CRT disconnect - Page 1
Forum section: electronics / repair

author: Ice-Tea
author_rank: Super Contributor
timestamp: November 06, 2016, 06:50:07 pm
content: Hello Folks,Probably very obvious but I'm taking out a display assembly out of a Tek TDS744 and I can't seem to take out this connector on the back.. Vertical Yoke I think. Doesn't seem to come off on the power supply side, can't seem to take it off on the display side.. Suggestions?

author: Ice-Tea
author_rank: Super Contributor
timestamp: November 06, 2016, 08:23:11 pm
content: Never mind: got it. For future reference: it's not a regular connector, it's some sort of spring/hook.So, to abandon the "let's just pull harder" approach was right

author: nctnico
author_rank: Super Contributor
timestamp: November 06, 2016, 10:52:45 pm
content: Be sure to follow the CRT discharge procedure first! A CRT tube can remain charged for a long time and provide a very nasty (high energy) electric shock!

author: Ice-Tea
author_rank: Super Contributor
timestamp: November 07, 2016, 03:40:51 pm
content: Thanks for the heads up guys. Was aware of the crocodile-like properties of tubes though

author: Gyro
author_rank: Super Contributor
timestamp: November 07, 2016, 07:37:42 pm
content: Just for reference and for the sake of the relatively fragile tube side contact in future... The simplest way to release those connectors is to slide it sideways until one arm unclips from under the side contact lip and then slide it the other way to completely release. Just pulling is asking for a vacuum seal failure.P.S. That side connector is also the safest way to release the vacuum on an old CRT. Just run a small hand drill through the middle of the contact, it's only a thin metal cup. The result is a prolonged hiss and no drama.
Tektronix P6021 AC Current Probe repair - Page 1
Forum section: electronics / repair

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: November 06, 2016, 02:33:45 am
content: Hi,Here is a quick repair project for you. I found this Tektronix P6021 AC current probe at a Hamfest today.Wide bandwidth current probes are very expensive, even used ones.It was labelled 'SCRAP' and had tag on it indicating that it only worked on one of the two settings:Fortunately the same vendor had a working Tektronix 465 scope on his table and I was able to confirm that the information on the tag was correct.This is good news. This means that the problem is almost certainly in the termination and the not the probe itself.I bought the probe for $30.00 CDN ($22.50 USD). When I got home I downloaded the manual and the schematic. When I opened the termination box I found the first problem. The connection to the center conductor on the output BNC was broken:I then checked the parts on the schematic:I found that the 61.9 Ohm resistor was open. I removed the resistor and checked it again with a DMM:I replaced the resistor and repaired the broken connection. I now have a fully working probe.Regards,Jay_Diddy_B

author: cheeseit
author_rank: Regular Contributor
timestamp: November 06, 2016, 10:51:15 am
content: Very nice, great that you got it working again!This thread reminded me I got one a while ago that were among lots of stuff that the seller threw in as a bonus. I just dug it out and it is fully working and in great condition. They sure sell for more than I would have thought on ebay.Thanks.

author: HighVoltage
author_rank: Super Contributor
timestamp: November 06, 2016, 12:05:22 pm
content: Very nice repair job and great pictures from the inside, thanks for sharing.I have a new P6022 but did not want to break the warranty seal to open it up.Now we know how it looks from the inside.Also nice to know, that the schematics diagram is available.

author: tautech
author_rank: Super Contributor
timestamp: November 06, 2016, 12:38:43 pm
content: Quote from: HighVoltage on November 06, 2016, 12:05:22 pmThe P6022 uses a different termination but IIRC has the same attenuation settings. They're mighty fine current probes both 6021 and 6022 and Jay did very well to steal his one for the little he paid.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: November 06, 2016, 04:19:42 pm
content: Quote from: tautech on November 06, 2016, 12:38:43 pmThe P6022 is a smaller, higher frequency, current probe. It has two settings 10mV/mA and 1mV/mA, different than the P6021.It uses a different termination box.SchematicLayoutPhotographsRegards,Jay_Diddy_B

author: HighVoltage
author_rank: Super Contributor
timestamp: November 06, 2016, 05:16:23 pm
content: Thanks for your explanation.I just downloaded the manual of my P6022.Kind of amazing that Tektronix still has a schematics in a newer manual.
Professional camera-corder uses video A/D converter to feed viewfinder: need PDF - Page 1
Forum section: electronics / repair

author: peteb2
author_rank: Regular Contributor
timestamp: November 06, 2016, 12:29:16 am
content: I've gone everywhere on the internet but haven't had any luck finding the device's .pdf even off the AnalogDevices website. No info from the maker of the camcorder. The unit isn't that old. I can find plenty of listings to buy the i.c. device in bulk.Made by AnalogDevices part AD80194KSTZ-110 it's purpose appears to A/D a version of analog video into that which can be displayed on a very small electronic display i.e an eyepiece viewfinder, probably lcd technology as opposed to oled..It's a long shot. The camera is made by Sony. Being a professional rig spares are eyewateringly expensive and Sony will sell only populated circuit boards! I am doing a friend a huge favour so she can get back shooting. I'm making nothing out of the whole exercise so asking if anyone might have this i.c.'s .pdf so with a bit more effort i can have this camcorder back showing images in it's viewfinder? I have 'scoped a few pins and there's plenty of pulse activity so i guess the device is alive...So far the owner stumped up for a replacement viewfinder which has an integral flatcable that plugs to the board that the A/D device occupies. (the original flatcable to it had been snapped through due to an accident and the camera would have been powered in that condition which means the outputs etc of the A/D would have been dis-connected to the viewfinder unit for periods of time.Here's a pic of the ic

author: amyk
author_rank: Super Contributor
timestamp: November 06, 2016, 01:09:16 am
content: Fromhttp://www.analog.com/media/en/pcn/ADI_PCN_07_0077_Rev_D_Form.pdfit appears to be a variant/custom numbering of the AD9883 family, of which you can easily find a datasheet. It's hard to see from your image, but the pinout does at least seem to match for the GNDs.The datasheet suggests the analog input could be VGA compatible (R, G, B, Hsync, Vsync), so you could try connecting a regular monitor to see if it displays anything.
METRIX MX57EX - Page 1
Forum section: electronics / repair

author: kardacz
author_rank: Contributor
timestamp: November 05, 2016, 04:23:27 pm
content: Good evening everyone! I own a multimeter METRIX MX57EX (photo) whose memory was corrupted by its former owner (EEPROM: 93C46). Someone would have it you kind enough to make me a copy of its contents ?. In advance merçi much to everyone who can help me!
Electronic lighter repair, unknown part - Page 1
Forum section: electronics / repair

author: Reider
author_rank: Contributor
timestamp: November 03, 2016, 11:30:49 pm
content: HelloI'm trying to fix an electronic arc lighter because it has a really high frequency and annoying sound when working. There is a part there I'm guessing is some kind of a timer circuit to drive the coils but I can't find the datasheet anywhere. I'm talking about the MI003 61906 U2 IC. Anyone has any idea what it could be? Picture attached.Thank You

author: amspire
author_rank: Super Contributor
timestamp: November 04, 2016, 12:12:04 am
content: There is only one capacitor visible, but that may be a timing cap or a supply filter cap. You could try drawing the circuit with the IC as a black box.If you have an oscilloscope, you may want to hold a probe near the oscillator when it is running to see if the sound you are hearing is the primary switching frequency or sound due to instability in an ultrasonic frequency oscillator.

author: zerorisers
author_rank: Regular Contributor
timestamp: November 04, 2016, 03:54:27 pm
content: Could it be anything likehttp://www.ti.com/lit/ds/symlink/ucc38084.pdf

author: Reider
author_rank: Contributor
timestamp: November 05, 2016, 02:26:50 pm
content: I'll try to trace and draw the circuit, maybe that will help. Thanks
Misleading information on the Fluke site ?  - Page 1
Forum section: electronics / repair

author: PA4TIM
author_rank: Super Contributor
timestamp: November 05, 2016, 12:57:12 pm
content: I repair measurement gear and that includes Fluke. Upto now most are scopemeters and these are stuffed with custom parts. No problem, that must be easy I thought the first timeBut upto now the answer was always negative (in the rare occasion that I got an answer).But last week I found this linkhttp://en-us.fluke.com/support/repair/and mailed them instead of the Dutch division.The answer was "contact your local Fluke division" So I did and the answer was as expected "we do not sell parts"I then pointed to their website in the link above that stated:QuoteNo answer upto now.I must be interpreted this the wrong way or Fluke is misleading their customers.
Keithley 196 repair report and question. - Page 1
Forum section: electronics / repair

author: Henrik_V
author_rank: Regular Contributor
timestamp: November 04, 2016, 12:02:38 pm
content: I happened to get my hands on a Keithley 196 DMM ..First run: Funny numbers in all Ranges...OK, this device is really service friendly, good service manual / schematics (in bad quality, a better copy for schematic and boad overview is highly wellcome).Needed a recap in the powersupply and a resoldering of the transformer connection.Pictures of the internals are already posted, I add only two:The powerboard is bended due to the mounting/fixing srews of the transformer (after soldering!)resulting in broken solder joints....Powerup, shortcut, 300mV range, zero stability, apply different voltages in all ranges, Ohms:AC has to follow a 5700A is availableCheck for input impedance: Apply a stable in range voltage in both polarities and insert a 10M in one lead ....The input protection diodes (FETS) are leaking... 300mV Range has about 11Meg for negative voltages, should be >1G.So this unit has seen some unhealthy occurences....The doc tell me Q5-Q10 are 2N4392 .. 4EUR for the metal canbut .65 in SMD ... is there a reason not to take the SMDs? Other JFETs prefered?Greetings from GermanyHenrik

author: saturnin
author_rank: Regular Contributor
timestamp: November 04, 2016, 03:49:34 pm
content: 11 MOhm is input resistance on 30V range. If you measure 11 MOhm on 300 mV range, Q13 JFET might be shorted (or turned on permanently).

author: Kleinstein
author_rank: Super Contributor
timestamp: November 04, 2016, 04:31:28 pm
content: The non SMT version of the fets might better fit the existing layout. Other instruments like the Keithley 2000 use the SMT version - so should be good enough here. Possible higher drift in threashold votlage should be no problem in a switching application (could be different if used as am amplifier).

author: Henrik_V
author_rank: Regular Contributor
timestamp: November 04, 2016, 09:03:58 pm
content: Thank you for the input.I will check the Q13... However since the 11M is only at negative input voltages in the 300mV and 3V range, my first action will be the input protection ones .... with SMDHenrik

author: lowimpedance
author_rank: Super Contributor
timestamp: November 05, 2016, 10:13:23 am
content: Better scans of the schematics can be found here.https://doc.xdevs.com/doc/Keithley/196/I fixed one of these DMMs at work some time back and the problem was the same with the transformer and cracked joints.
FPC connector tds3012B - Page 1
Forum section: electronics / repair

author: R_G_B_
author_rank: Frequent Contributor
timestamp: November 04, 2016, 04:00:50 pm
content: Can someone help with this:I have been searching for a FPC connector on the main PCB board of a TDS3012BIts a vertical type 9 pin SMD see pictures for details, The pins are in a staggered arrangement on the FPC connector if that makes sense. see pictures for details.I was going to reconstruct the connector by disordering and placing them back into the wholes of the connector however one of the pins is missing.Thanks

author: singapol
author_rank: Frequent Contributor
timestamp: November 04, 2016, 07:10:00 pm
content: Tried here?http://uk.farnell.com/ffc-fpc-board-connectors

author: R_G_B_
author_rank: Frequent Contributor
timestamp: November 05, 2016, 09:05:20 am
content: I'm looking for one like this except it should have 9 pins instead of 8 and 1mm pitch spacing.
Help identifying SMPS IC (Solved) - Page 1
Forum section: electronics / repair

author: madmaxbryan
author_rank: Contributor
timestamp: November 04, 2016, 05:47:44 am
content: I've been working on repairing an LED display at work, but I cant seem to find any information on the SMPS IC. Its a 10 pin QFN with "M7CN 950" marked on top. Its taking in 24 volts and I believe outputs 5 volts. Can anyone identify this IC?

author: EPTech
author_rank: Regular Contributor
timestamp: November 04, 2016, 09:22:23 am
content: Hi there,It might be a MP4460 from MPS, judging by the circuit in your photograph.FYI: G-search "step down converter QFN10 M7". First that came up.

author: madmaxbryan
author_rank: Contributor
timestamp: November 04, 2016, 09:49:49 am
content: The pinout does appear to match the circuit perfectly, I think you found a match. Thank you for your help.
Marconi/IFR/Aeroflex 2030 PLL repair - Page 1
Forum section: electronics / repair

author: adilmalik
author_rank: Contributor
timestamp: November 03, 2016, 10:45:36 am
content: Hi everyone!

author: PA0PBZ
author_rank: Super Contributor
timestamp: November 03, 2016, 10:53:14 am
content: I didn't download it to check (142M!) but this suggests it's the service manual:http://www.ko4bb.com/getsimple/index.php?id=download&file=Marconi/Marconi_2030-2031-20_Marconi_2030-2031-2032_Signal_Generator_Service_Manual.pdf

author: adilmalik
author_rank: Contributor
timestamp: November 03, 2016, 11:01:10 am
content: Quote from: PA0PBZ on November 03, 2016, 10:53:14 amWow i actually take pride in my googling skills and yet 2 days of googling has found me nothing....This is it! Thankyou!
(LT) Spice model for ON Semi DAP008, DAP08 ? - Page 1
Forum section: electronics / repair

author: carl_lab
author_rank: Frequent Contributor
timestamp: November 03, 2016, 06:16:58 am
content: Can anybody help me finding an LTspice model for this SMPS controller, please?http://fa.itservice-bg.net/baza/ic_power/sm_data/DAP008_data.pdfI tried googling "DAP008 spice model" and "DAP08 spice model" without success.
Trotter 685 Treadmill - Page 1
Forum section: electronics / repair

author: atw58
author_rank: Newbie
timestamp: November 08, 2016, 02:19:23 pm
content: Greetings to all the EE community,I have this gym quality treadmill which displays an "Err Code 08" (power train) when powered up and it doesn't respond to any normal commands. Going into diagnostic mode, individual input, logic, sensor tests pass except the DC amps where the motor does not run at all. When working the speed can be increased/decreased and the display shows the DC amps supplied to the motor. My thinking is the Power Control Module (PCM) detects an error condition related to supplying power to the motor then sends a signal to the display/logic board preventing power applied to the motor.The treadmill is no longer supported by Cybex (Trotter owner) and they can't/won't provide any service or troubleshooting manuals.Here are some basic troubleshooting observations.240V AC is present at the output of the line filter.The large capacitor charges to 270V DC.LED 1 and LED 2 are both "On" on the PCM motor control board.There is some discolouration at the 2 DC motor pins on the main AC/cap/motor green connector.No signs of burnt parts on the PWM board.Hoping someone who has experience with this unit see this plea and can provide some guidance. Even a schematic would be great to troubleshoot this further on my own. Posting here is a bit of a long shot but anything can happen on the internet.

author: eKretz
author_rank: Frequent Contributor
timestamp: November 08, 2016, 10:51:52 pm
content: I've repaired a few of these (treadmills, not your exact brand/model) for others and all of the failures were blown rectifiers and a few diodes in circuit with them. Your numbers make me think yours could have a similar problem. A full wave bridge rectifier with filter cap should produce closer to 340V DC at the output of the filter cap with no load with a 240V AC input. Unless there's a transformer in between dropping the voltage coming in to the rectifier?
Quadro 6000 fix [HELP] - Page 1
Forum section: electronics / repair

author: 3dgeo
author_rank: Frequent Contributor
timestamp: November 02, 2016, 03:01:12 pm
content: Hi,Firstly what happened, later about very interesting simtoms...After replacing everything else in my workstation my Quadro 6000 is slowly dying.At first it crashed rarely (in few hours), but crashes keep coming more often and in about 24h drivers no longer was working on this card, I still can boot with drivers uninstaled or in safe mode, but I can't instal drivers anymore - it do not detects compatable device.Note that all this time card was watercooled, even in old workstation. I monitored GPU temp with GPU-Z last GPU living hours, even in game it never exceeded 45c, 35c idle.Caps seems fine, no bulging or other defects.It's not LCD, cable or power supply fault (changed all of them).Facts:1. Artifacts apears even in bios, but not in all bios windows - some looks normal, it seems only bios window with only letters and black background renders as usual.2. Defected lines are somewhat constant position, but they change color slightly (mostly pink)3. If I make screenshot - no defects... Does this means GPU chip is fine? Note this is NOT a cable or display fault!4. GPU overheat is very unlikely becouse it is watercooled5. These artifacts came graduatly, at first only driver crashed and rarely PC itself6. Artifacts appears via Display Port or DVI (other outputs not avalable)7. If I move a mouse, in it trails artifacts temporarily disappearsHas any of You have any ideas what might be wrong?

author: TiN
author_rank: Super Contributor
timestamp: November 02, 2016, 03:04:47 pm
content: Memory or more likely BGA contact on GPU related to memory interface is bad.Not much you can do, but to bring card to proper repair shop which can try to remove GPU, reflow new BGA balls on it using stencil, and put GPU back on PCB again.Even then there would be no warranty from the shop, as it's still a gamble, if you want to have card live more than few days after.Time to think about getting new card

author: 3dgeo
author_rank: Frequent Contributor
timestamp: November 02, 2016, 03:17:17 pm
content: Quote from: TiN on November 02, 2016, 03:04:47 pmI don't have any experiance in electronics repair, but I really doubt it's BGA balls, more likely it could be FC BGA, but it was watercooled so no extreeme temperature diferences to break them. And screenshots are fine, so it must be some kind of output to display fail.+It failed after I put it in new workstation, I change thermal paste and reinstalled waterblock - it's more likely I damage something by doing it.

author: TiN
author_rank: Super Contributor
timestamp: November 02, 2016, 03:20:37 pm
content: Screenshots are not taken from card's framebuffer, where you have a problem.So of course they are fine.

author: 3dgeo
author_rank: Frequent Contributor
timestamp: November 02, 2016, 03:22:01 pm
content: Quote from: TiN on November 02, 2016, 03:20:37 pmHow are they taken?
Where to purchase Fluke T5-1000 Replacement Housing/Shell - Page 1
Forum section: electronics / repair

author: joshforester
author_rank: Contributor
timestamp: October 30, 2016, 10:21:31 pm
content: I've searched high and low to no resolve, and Fluke US hasn't panned out either. Does anyone happen to know where to purchase Fluke T5-1000 Replacement Housing/Shell? Or possibly have one to sell?Thanks!

author: grifftech
author_rank: Frequent Contributor
timestamp: November 01, 2016, 03:24:50 pm
content: make your own