hybridfree/eevblog-posts huggingface dataset:
Tek 2215 oscilloscope with A18 preregulator board repair - Page 1
Forum section: electronics / repair

author: Zo-lee
author_rank: Contributor
timestamp: April 09, 2016, 01:27:28 am
content: I recently bought this Tek 2215 on Ebay for AUD120 (including postage). “For parts or repair”. I decided to repairThis is my very first scope. I always wanted one for some faint reason and now I only have to make it working and play with it.It looked very clean inside and out, far better than I expected.Of course, I turned it on first and nothing, then checked the fuse with continuity test it was ok.I opened up the “sucka” and didn’t see or smell anything suspicious for the first sight. As I followed the way I find the A18 preregulator board physically but didn’t find the schematic in the service manual.It took several days for me to find it in the MANUAL CHANGE INFORMATION at the far end. If it is obvious for you probably you lot smarter than me, good on you.Hopefully you can see too the burn marks around the Q933 transistor’s terminals on the photo . It was quite easy to find.As I was unscrewing the board I heard something fell to the main board but I needed to disconnect 4 cables first to free the board. I needed some time to find a little white plastic square covered with heat paste (342-0582-00 insulator) down on the main board. On the other side of the A18 I found the Q933 (IRF820) attached to a brown boxy thing (343-1025-00 retainer) and a green something hanging on a wire also cover by the heat paste (still can’t find out what the hell it is, probably the shield)The A18 is upside down now on the photo No2. I found out the order of the parts: retainer is the closest to A18 board, holding the IRF820 covered by heat paste then the insulator probably glued to the shield (or something?) heat paste again and the whole sandwich screwed to the chassis (red arrow ) This is a pain in the arse design. As I assembled I had to make a long thin hook to hold the shield in position while tighten the screw. Lucky I’m an alien with three hands.As far as I know they found another solution for the 2215A.OK, so I de-soldered the transistor and cleaned the board bla-bla and I faced another problem: you (or maybe just me) can’t adjust the transistor in to the holder (brown boxy retainer) after soldered it to the board, you must put these two together first and adjust the transistor’s legs carefully to their holes on the board, keep them in position and start the soldering. Unfortunately I don’t have four hands so I had to find out how. See on photo No3Beautiful.I also replaced some caps, just for fun and the fuse as well because it blown off on a mysterious way during the process.I hope there is someone out there who will find this helpful.Cheers
Crown XTi 6002 v2 Amp Repair - Page 1
Forum section: electronics / repair

author: nolafreelanceit
author_rank: Newbie
timestamp: April 03, 2016, 04:49:14 am
content: I am trying to repair my amp and these parts are blown but I cannot find them anywhere on the net that has less then 16 day shippinghttp://www.irf.com/product-info/datasheets/data/irfb20n50k.pdfhttps://www.fairchildsemi.com/datasheets/IS/ISL9R3060G2.pdfIf some one would have some or know where to get in the US that would be fantastic, Thanks!

author: Kibi
author_rank: Unknown
timestamp: April 07, 2016, 08:09:46 pm
content: Digikey appears to have them.http://www.digikey.com/product-detail/en/vishay-siliconix/IRFB20N50KPBF/IRFB20N50KPBF-ND/812859http://www.digikey.com/product-detail/en/fairchild-semiconductor/ISL9R3060G2/ISL9R3060G2-ND/965378
HP3561A  DMA Autozero Timeout Error  - Page 1
Forum section: electronics / repair

author: Johnny10
author_rank: Frequent Contributor
timestamp: April 07, 2016, 02:01:52 pm
content: After having a problem with my HP 3561A that I use on the bench.I pulled out one of first pieces of electronic gear I purchased.A non-working 3561A with the following error on start-up.DMA ErrorWatchdog Power upSoftware Revision 2410Return Error Code1 2 03Service manual shows this as an Autozero DMA timeout error.Will be studying manual for better understanding of this error code.
HP 3561a Signal Analyzer Display Troubleshooting Solved - Page 1
Forum section: electronics / repair

author: Johnny10
author_rank: Frequent Contributor
timestamp: March 30, 2016, 12:47:38 pm
content: I have my HP3561a on the bench because of a Test error and just wondered if anyone else has experienced this issue.When I power on the unit the self test returns Error # 07 28 Ram: GIn the Service Manual this comes up as Display memory error in NMOS 16K dynamic ram module, G position.Is this the only module I should be concerned with or will there be more problems,

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 30, 2016, 01:25:15 pm
content: Looks like a classic example of video ram problems, it could be a stuck address/data line but most probably just the ram chip.

author: Johnny10
author_rank: Frequent Contributor
timestamp: April 07, 2016, 01:50:47 pm
content: OK, Solved Post.I exchanged Ram board with one from another of my 3561A units.Everything back to normal on the display.Now I have another question which I will post in a new thread.Thanks
I don't know about Fluke! - Page 1
Forum section: electronics / repair

author: tony3d
author_rank: Frequent Contributor
timestamp: April 05, 2016, 08:00:54 pm
content: I sent my Fluke 287 in for the super cap repair, and it came back about a week ago. Just the looked at the meter info screen, my serial number says 0, and the calibration date says 3-23-07. This can't be right. They said they replaced the PCB board. should I send it back to have this info replaced?

author: Len
author_rank: Frequent Contributor
timestamp: April 05, 2016, 08:07:35 pm
content: That doesn't seem right. They should at least do their normal calibration after replacing the circuit board.

author: tony3d
author_rank: Frequent Contributor
timestamp: April 05, 2016, 09:42:15 pm
content: Well, I think they did, I have the stickers on the seams, and got the certificate, but the meter has 2007 as the date, and my serial is showing up as 0! That alone is bad, looks like a stolen board or something. Just don't want any trouble should I have to send it again. If it has to go back to have this fixed its really an inconvenience. Oh well.

author: tony3d
author_rank: Frequent Contributor
timestamp: April 06, 2016, 05:28:58 am
content: Fluke wrote me back an emailing stating that it's normal not to have the serial number or the calibration date on units with new PCB boards. Has anyone else found this to be true with replaced PCB BOARDS?

author: casinada
author_rank: Frequent Contributor
timestamp: April 07, 2016, 04:00:09 am
content: It is highly unusual.My 289 Came back with a performance verification and new batteriesIt is not normal for a company like Fluke to send out a repaired instrument without at least testing it.Just call tech support and tell them what happened. Try to be polite. They are very good at fixing problems

author: Psi
author_rank: Super Contributor
timestamp: April 07, 2016, 07:18:07 am
content: Just say you have regulatory requirments to do internal tracking of test equipment, and a unit with no serial number is useless.There is no way in hell fluke can argue with that, nor would they even try.ISO 13485 is one standard you could mention.Its quality management systems for medical devices.One requirment is to track the serial numbers of your test equipment.

author: Kilrah
author_rank: Unknown
timestamp: April 07, 2016, 07:53:04 am
content: But it would be the SN on the case that does this job.

author: Psi
author_rank: Super Contributor
timestamp: April 07, 2016, 07:56:55 am
content: If the firmware S/N doesn't match the case S/N it's not a valid piece of test gear.This is a Fluke 287, so a high end datalogging meter. The 87-V is like half the price.You might record some data and dump it out over IR cable to the fluke reporting software. (The fluke reporting software can generate complete reports with graphs etc..)Your report is going to have the wrong S/N on it, or in this case a S/N of zero!
D-shapped connector identification - Page 1
Forum section: electronics / repair

author: hcbjunior
author_rank: Newbie
timestamp: April 06, 2016, 06:53:23 pm
content: Hi All,I need to repair a Toshiba Nemio XG keyboard's cable, but i could not find whitch connector it uses.There is an image attached. There are 26 pins on it.Thanks.

author: Gyro
author_rank: Super Contributor
timestamp: April 06, 2016, 07:29:50 pm
content: That looks rather like the small (miniature) Amphenol parallel port connector that HP used to use on some of their laser printers, not sure about the pin count though.
SMT PBGA Chip Replacement near Kent England - Page 1
Forum section: electronics / repair

author: Clint
author_rank: Regular Contributor
timestamp: April 14, 2016, 10:39:54 am
content: Hi guys I have a piece of equipment with a blown Infineon Tricore SAK-TC1797-512F180E I need replaced, anyone know someone who can do this for me ?

author: AndyC_772
author_rank: Super Contributor
timestamp: April 14, 2016, 10:44:24 am
content: I was going to recommendwww.sti-limited.co.uk- but their web site currently appears to be down.Might be worth giving them a call anyway; I've used them before for BGA rework with excellent results.
Help to identify a component - Page 1
Forum section: electronics / repair

author: nmac
author_rank: Newbie
timestamp: April 04, 2016, 06:20:58 am
content: Hello all,This is my first post... and my first consideration and question is: Should I post it here?I trying to repair a hair dryer with some rotate function and ceramic stuff... and found this component on image attached.a slow motor is the issue... probably - and I think - after a broken resistance made a intermittent contact turning on/off this device many timescaused a sequence of inrush current on capacitor and a consequently degradation of it. I don't know, I speculate it could be a capacitor. hehehe But its not the usual info printed on, right?I can't find on Internet some spec or datasheet for this one.Someone have any idea what is this?Thanks!

author: Cloud
author_rank: Regular Contributor
timestamp: April 04, 2016, 06:22:44 am
content: My first guess would be a filter

author: Gyro
author_rank: Super Contributor
timestamp: April 04, 2016, 09:10:42 am
content: That looks like a step-up converter - 4.7kV out. I'd guess it's one of those 'Ionic' hairdryers.P.S. I doubt it has anything to do with your problem, it's fed directly from the supply and just feeds some sort of spiky electrode near the hot end. The fan motor is usually fed from a tap on the element winding via a (possibly bridge) rectifier. Check for failed diodes. A common reason for slowing down is loose hair wrapping itself around the motor shaft until there's no free play left.

author: SeanB
author_rank: Super Contributor
timestamp: April 04, 2016, 03:32:12 pm
content: Agree on the loose hair, but also a drop of oil on each oilite bush ( one under the fan so you will have to pull the fan, and get the loose hairball out first before you oil it) of the motor will work wonders. Diodes are also common, but generally you can check in circuit as they tend to go short circuit or break in half.

author: nmac
author_rank: Newbie
timestamp: April 04, 2016, 08:19:43 pm
content: Thanks for all!Gyro, makes sense. I'll verify diodes. SeanB, the problem isn't mechanical, but a drop of oil isn't a bad idea.I'll try those things and let you know if it works for me.Thank you!

author: nmac
author_rank: Newbie
timestamp: April 04, 2016, 11:51:25 pm
content: That's it! Just a diode.Thank you, guys!I really enjoyed this forum!

author: Macbeth
author_rank: Super Contributor
timestamp: April 05, 2016, 12:24:46 am
content: Quote from: nmac on April 04, 2016, 11:51:25 pmPast tense? Ok, fine... Don't forget to close the door on your way out!

author: nmac
author_rank: Newbie
timestamp: April 05, 2016, 08:43:41 pm
content: hahahaha... using cell phone..sorry..I swear I'm still enjoying this forum hahaha
SMD Component trouble monitoring - Page 1
Forum section: electronics / repair

author: deepskyridge
author_rank: Regular Contributor
timestamp: April 02, 2016, 04:22:11 pm
content: I have a HP E3631A that mostly works except for the readback section, I know the problem is in the A/D Converter.The components are small SMD ones and don't make it easy to monitor ic pins etc. without causing further damage.What do you use for this purpose, I was wondering if there a very small mini grips that would work for this purpose.ThanksGary

author: tautech
author_rank: Super Contributor
timestamp: April 04, 2016, 05:47:58 am
content: Something like these Tek grabbers is what you'll need or solder a short flying lead to your POI.http://www.ebay.com/itm/Tektronix-195-3659-02-2-leads-w-grabber-tips-for-P6453-BLACK-/361318681059?hash=item54204589e3:g:RQIAAOSwBLlVece6http://www.ebay.com/itm/Tektronix-SMT-SMG50-Clip-Chip-Grabbers-Part-206-0364-00-206-0364-01-each-/201263961054?hash=item2edc4453de:g:QtcAAOSwrx5UXOPWThose that are not supplied with leads can be connected to with push on 0.025" female terminals, you just mght have some in your junk pile.
Thermal image camera Argus - Page 1
Forum section: electronics / repair

author: Nelix
author_rank: Newbie
timestamp: April 13, 2016, 12:23:23 pm
content: Hi AllI am new here and was hoping for some help.I have an issue with Rodents in the cavity in my home and was thinking of buying a thermal camera to see if I can find where in the cavity they are hiding/coming in.I have the opportunity of an Argus EEV camera, however it does not appear to work, the screen does not show an image, it just shows static. I imagine that this is a "How long is a piece of string" type question but does anyone know if this may be repairable ans if so what sort of ball park figure would I be looking at. It also does not have a battery.Kind RegardsNelix

author: SeanB
author_rank: Super Contributor
timestamp: April 13, 2016, 06:51:54 pm
content: Rodent cure is to get some Finale wax pellets, and place the pellets, with a dollop of peanut butter on them, in the cavity, along with some water in a bowl. Replace as they get eaten, and after around day 3 there will be no more activity.As to the camera, contact Fraser here on the forum, he might have some help for you.
Old Casio fx2000 calculator - Page 1
Forum section: electronics / repair

author: alank2
author_rank: Super Contributor
timestamp: April 02, 2016, 04:32:48 pm
content: I bought it today for $3 in a garage sale and have been playing around with it. I fixed the power switch which was intermittent by cleaning it up, but the LCD display is hard to read except at extreme angles. At normal angle it looks like all segments are on, but if you hold it at 75 degrees from normal you can make out the digits and it works. I've had it all apart and took the LCD odd and cleaned up the contacts/elastomer between the display and pcb. I tried some flux and resoldered all the connections around the IC. I replaced the 3 caps which now that they are off look like 1uF with some 10uF ceramic ones I had laying around. There is what looks like a SIP-6 and one more resistor where the pcb is marked 100 that measures 100 ohms. The SIP reads all sorts of stuff so I'd probably have to take it off to measure it. Any other ideas or things to try?

author: sherlock
author_rank: Contributor
timestamp: April 02, 2016, 07:23:49 pm
content: Here's a trick to try but you have to be careful doing it. Sometimes the segments in the display loose their connections internally. First, take out the battery. Then take some aluminum foil and place it under the display and around it to protect the surrounding board and components. Now take a heat source (heat gun or hair dryer) and heat the display. You'll soon notice it gets black around the edges. Keep heating until the whole display turns black. Then let everything cool down for about 20 minutes or so. The display should return to it's normal color. Remove the foil, put the battery back in and try it out. If that was the problem, the display should work normally. I've done this on several different devices with about an 80% success rate. I guess for a $3 item it's worth the shot. Good luck.
Ansmann Energy 8 Charger. - Page 1
Forum section: electronics / repair

author: FrankE
author_rank: Regular Contributor
timestamp: April 02, 2016, 05:20:29 am
content: Figured I'd have a go of this since I found two-pronged driver to get the case open.I found a leak mark under the large electrolytic C2. Replaced with a a longer life 22uF 400V nichicon.Replaced the other cap in that board.Headers from the LED / batteries under charge +ve board were corroded and there is corresponding pad damage on the main board.Waiting for copper sheet in the post to cut new padsOrdered up 1 row and two row bent headers and replaced.I've got caps to recap throughout but i'll see how things go.Channel 2 is on all the timeChannel 5 and 6 do nothing.
P6106 probe 10x pin assembly - Page 1
Forum section: electronics / repair

author: ledtester
author_rank: Super Contributor
timestamp: April 01, 2016, 12:20:45 am
content: Hi,The 10x contact pin assembly on my P6106 Tek probe mysteriously came apart, and I'm wondering if it is fixable. Somehow the black retention ring came off and I heard something drop on my hardwood floor.Below are some pics of the pieces that I've got. I have a feeling that I am missing something. The second pic is how I think things are suppose to go back together, but the 10x pin isn't being pushed out to make good contact with the 10x ring on my 475.Any ideas?

author: Andy Watson
author_rank: Super Contributor
timestamp: April 01, 2016, 12:42:08 am
content: I'm guessing that you are missing at least some sort of spring to push the pin out. Some Tek probes use "pogo" test pins to make the contact - this might be a source of parts if you can't find the original spring.
I need some help identifying a crystal. - Page 1
Forum section: electronics / repair

author: DC Jack
author_rank: Contributor
timestamp: March 30, 2016, 06:28:32 pm
content: I am trying to fix a friends "bow string weight guage", basically an electronic scale that hooks on to a string. It slipped out of his hand when he was testing a bow and shot it across the room into a wall like an arrow. Everything looked fine but the unit won't turn on now.I took the thing apart and can't find any physical damage and all the components pass my DMM sniff test and from past experience I know that crystals can fail due to shock damage much more easily than other electronic components. I'm hoping to replace the crystal and be done with it because if it is the PIC that is damaged then he is screwed because there is no way in hell I am going to be able to get my hands on the programming to make a new one.The problem I am having now is that I can't figure out what the crystal is. I Google'd the only markings I could find on it and nothing of worth comes up. I also have no experience with PICs so I can't make any educated guesses as to what it could be. Any help or advice would be appreciated.P.S. I have attached pictures of the crystal, board, and the PIC.P.P.S. I am getting all the appropriate voltages and am assuming that the PIC is simply not turning on.P.P.P.S. I posted this on the BadCaps forum and it was suggested it is a 4 Mhz crystal because of the 4 in the markings.

author: xyrtek
author_rank: Regular Contributor
timestamp: March 30, 2016, 06:52:44 pm
content: Is the xtal the clock source for the pic? or is it connected somewhere else in the circuit?if yes to the first question then check the datasheet for the pic to see possible clock options.EDIT:http://ww1.microchip.com/downloads/en/DeviceDoc/39544B.pdfI say yes by looking at the pics, then check page 99 for details.If you have a scope solder the xtal back and probe around it.If you can identify the values of C11 and C12 (i think) you could reduce the choices by looking at table in page 99

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 30, 2016, 08:00:00 pm
content: * put a 4 MHz crystal in and see if it works* make a simple oscillator using a 74XXX TTL/CMOS and see if the original crystal oscillates* get your function gen out and inject 4 MHz into the correct pin* did you check if it oscillates in the original circuit?
LG HT355SD -  DVD player repair (my first repair attempt) - Page 1
Forum section: electronics / repair

author: MarvinTheMartian
author_rank: Frequent Contributor
timestamp: April 03, 2016, 05:11:00 am
content: G'day all,I'm about to embark on my first attempt at a 'serious repair'.We have a DVD player (LG HT355SD) that has been gradually failing in that the sound synchronization is getting out of whack (used to happen if youPause, thenPlayand I could fix it by pressingStopand thenPlayagain).Last night the 'fix' above no longer works and the synchronization is now always out of whack.I've opened the case and done a visual inspection but can see nothing obliviously wrong (there are a ton of electros -Changbrand) but none look to be leaking. I've yet to use the ESR meter on any of them.I next did Dave's "thou shalt test voltages" on the power supply board and the voltages are fine. I haven't tested anywhere else at this stage.I've got the service manual and am going to see if I can get my head around where this synchronization may be happening, before I test any further.This could be a long term project as I learn or ultimately afailbecause it is too advanced for me at this stage.If anyone has some tips or advice, I would appreciate it.Many thanks.Edit: Forgot the picture - doh!
Fluke PM3082 - Page 1
Forum section: electronics / repair

author: Armadillo
author_rank: Super Contributor
timestamp: March 22, 2016, 02:21:12 pm
content: Hi;My oscilloscope screen will lights up momentarily and then the screen will be dead blank. I suspected the problem is from the protection circuitry A6 board. But the fluke service manual really sucks. Not at all clear with its description. I just broke the feats...really!. the manual say to pull it out, so I did and crack the feats....LOL.Anyone would like to advice me how to dismantle the A6 board. Cannot see any clips or screw holding it onto its slot. What would likely be the problem? opto?, diode?. The fans would rotate couple of turns before it went dead every time I press the on button. Even the fan connector cannot be pulled out.... Now, is there a clip somewhere?I would also like to clean up the fans, replace it maybe... How do you dismantle the fan.... its not even described in the service manual...thanks for any help rendered...

author: grumpydoc
author_rank: Super Contributor
timestamp: March 25, 2016, 04:06:47 pm
content: There is a torx screw holding it down in the chassis (look between the board and the plastic wall between it and the CRT, there are also two plastic clips (front and back) that need to be sprung out of notches in the PCB.

author: Armadillo
author_rank: Super Contributor
timestamp: March 29, 2016, 12:55:57 pm
content: Quote from: grumpydoc on March 25, 2016, 04:06:47 pmThanks grumpydoc. Your information was helpful. There are precisely a torx and 2 plastic clips holding the A6 Board.I discovered that there are not many information on the WWW regarding this scope. So I would pose some photos here hoping it may help others.As for mine, there was a 14FO fault caused by the BF820 transistor. Element14 always has the parts I needed and swiftly sent over.Job Done!.
Dirty voltage PC Power Supply - Page 1
Forum section: electronics / repair

author: kasumyku
author_rank: Regular Contributor
timestamp: March 26, 2016, 08:58:35 pm
content: Hello everyone,I just got a brand new PC power supply and I have a little problem with it.First of all I'm using it to power up a car amplifier, the issue is that there is a constant humming noise coming from the subwoofer and the only way to eliminate this is by using a car battery, so the problem is not the amplifier...Can anyone please tell me how can I get rid of the humming noise, does removing ground prong would make any difference or is there any modifications that can be done to the power supply?p.s.: worse comes to worst I'll be end up using it as a bench power supply, but for now I would really like to know what makes this humming noise ...Thank you!!

author: uncle_bob
author_rank: Unknown
timestamp: March 26, 2016, 10:17:18 pm
content: HiYour PC power supply may (or may not) have some problems:1) It may require a certain minimum load on certain outputs to regulate in a quiet fashion.2) It may be broken and be noisy as a result3) It may just plain be noisy all the time on the +12 even when working correctly4) It might be overloaded (this is unlikely).If you want to try something, get a few 4,700 uF 16 V caps and start throwing them on the 12V supply lead. If you get past 10 caps and still have the problem. Get another supply. PC supplies are not designed for low noise audio work. If you go shopping for something else, get a supply designed for audio.Bob

author: Seekonk
author_rank: Super Contributor
timestamp: March 27, 2016, 04:48:10 am
content: Not a fan of these conversions, you accept what is printed on the label is real. This supply can only regulate one output voltage, the +5V. The other one just tags along. Putting a couple amp load on the 5V would make it run better. It was never designed to function like you want.

author: daveshah
author_rank: Unknown
timestamp: March 27, 2016, 08:23:23 pm
content: Is the amplifier connected to a grounded signal source (i.e. a desktop PC) when this happens? If so, the proper way to deal with the noise is not removing ground from one of the devices (which may work, but presents a safety hazard), but using a differential input to the amplifier (either a passive transformer or active opamp circuit).

author: Kevman
author_rank: Regular Contributor
timestamp: March 28, 2016, 01:10:38 pm
content: Try it with a battery powered device first, like a phone, and see if the humming goes away.
HP 54110D - Page 1
Forum section: electronics / repair

author: Daxxin
author_rank: Regular Contributor
timestamp: March 27, 2016, 07:21:38 pm
content: This cpu is a motorola 68000 ? while booting i get software error at address 0000AH0 ..its a eprom address or cpu address?

author: uncle_bob
author_rank: Unknown
timestamp: March 28, 2016, 01:11:40 am
content: HiErrr ..... AH0 as the last digits? That does not look like hex.Ax0 is most likely on the CPU. If not, it's low ram off the CPU.Bob

author: Daxxin
author_rank: Regular Contributor
timestamp: March 28, 2016, 04:03:00 am
content: Hi , i was thinking something similar too , cpu is mc68000lbut looking at allocation table looks like rom area.

author: picburner
author_rank: Frequent Contributor
timestamp: March 28, 2016, 08:20:35 am
content: If the problem is a corrupt EPROM here you can find a copy of the firmware:http://www.ko4bb.com/getsimple/index.php?id=download&file=HP_Agilent/HP_54110D_Digitizing_Oscilloscope_EPROM_54100-66530_Re.zipNot knowing if the firmware release is the same, you should burn a full set of EPROMs.
Levell TM10 DC Microvoltmeter Calibration - Page 1
Forum section: electronics / repair

author: enut11
author_rank: Super Contributor
timestamp: March 28, 2016, 06:36:48 am
content: Hi allThe UK company Levell Pty Ltd made some interesting (now vintage) analogue Null Meters and DC Microvoltmeters. I recently acquired a TM10 model through a dealer ex TAFE SA. On testing, it is way out of cal on the volts range (~12% high). Seems ok on the mV range.I have not been able to find any manuals or info on the TM10 or any other Levell DC microvoltmeter so would appreciate any help out there.Would also like to know how to set Z1 and Z2 correctly as well as the function of the LOG setting.There are lots of pots on the PCB but they are all unlabelled and some of them are covered in a clear lacquer. Also lots of transistors and one lonely IC - UA776HC.I have posted some pix to start things off.enut11
Identify one capacitor, how to check working voltage - Page 1
Forum section: electronics / repair

author: gomarota
author_rank: Newbie
timestamp: March 20, 2016, 06:39:57 pm
content: Hi, i have one cap wich seems damaged, but in the top of the cap there is just a number 221(Capacitance = 220pF) for capacitance, i have to buy new one but dont know wich is the working voltageany hint/tip?is a car dashboard

author: SeanB
author_rank: Super Contributor
timestamp: March 20, 2016, 06:47:21 pm
content: 220nH inductor actually.

author: TurboTom
author_rank: Super Contributor
timestamp: March 20, 2016, 07:20:09 pm
content: Sure? Considering the size, I'ld rather guess it's 220µH. It's an inductor, not a capacitor, that's agreed.Cheers,Thomas

author: gomarota
author_rank: Newbie
timestamp: March 20, 2016, 08:37:59 pm
content: both are right! thanks i havent had good day today!

author: uncle_bob
author_rank: Unknown
timestamp: March 28, 2016, 01:32:47 am
content: Quote from: gomarota on March 20, 2016, 08:37:59 pmHiSo now, rather than the working voltage, you need the current spec's on the inductor. You may want to figure out what it is doing as well. That will give you an idea of the frequency it needs to operate to.Bob
[?] AC voltage control block???? - Page 1
Forum section: electronics / repair

author: allenpan
author_rank: Contributor
timestamp: March 27, 2016, 05:31:38 pm
content: [?] AC voltage control block?i have a steam mop Oreck Steam100, and it is not working and i have determined it must be the AC voltage controller block died... it has a potentiometer to adjust the speed of pump (120VAC 60Hz, voltage control?)the block itself has 6 wires, 2 for potentiometer, 2 skinny red wires and, 2 sticker wires,does anyone have diagram of how it work? like the pin out? so i can by pass it? or part number for the replacement?
Weird behavior with high voltage LCD driver - Page 1
Forum section: electronics / repair

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 26, 2016, 09:27:32 pm
content: I'm looking to see if I can determine if the backlight of an LCD itself is shot (it flickers a lot, my hunch is it's in fact the bulb) or if it's the actual driver. But since I'm dealing with unknown high voltage I don't want to just stick my scope on it. My goal is to have the scope on it using a voltage divider and wait till it starts flickering to see if anything changes.So I built a basic voltage divider, a 100k and 10k resistor. I had my hand held multimeter (note: not grounded) connected to the divider across the 100k resistor, and as soon as I place only ONE wire from the divider on the high voltage output, I get an arc and the LCD actually dims! What is it arcing to if the other end is not connected to a return path? It's also drawing a decent amount of power if it's enough to make the LCD dim, but how? Where is that power going? If I take a short piece of wire and touch one end to it I get the same thing. (insulated wire of course). I'm kinda stumped. I know high voltage can arc through the air but is that really what's happening here? How does the circuit even work then, the traces are not shielded or anything like that.

author: bktemp
author_rank: Super Contributor
timestamp: March 26, 2016, 09:41:58 pm
content: The voltages used for driving CCFL tubes are around 1kV and the frequency is somewhere between 30kHz und 70kHz. Since the tubes are driven using a constant current, even tiny amounts of capacity (<10pF) load the output signficantly.Measuring the output voltage of a CCFL inverter can be difficult, because you need a high impedance at the operating frequency. Even a standard 100:1 probe often has too much capacity and affects the output voltage.

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 26, 2016, 11:55:39 pm
content: But where is the current going though when I put a wire on it? Even a short wire with nothing on the other end loads it down! Is it basically acting as a radio transmitter because of the high voltage and high frequency and the wire is an antenna?

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 27, 2016, 01:44:28 am
content: lol so I just blew a 10k resistor, I decided to put my voltage divider with dmm across and see what happens, figured maybe if it's all connected up and then I turn it on it won't be arcing or doing anything weird, did not figure I'd blow a 10k resistor this way, there must really be a large amount of current coming out of there. My multimeter seems to have survived. I think.I should have tried without it connected first.I'm almost convinced it's the bulb that's busted though and probably not worth replacing. This was more just for fun, and think I've gotten beyond voltage levels that I'm equipped to work with safely. I can always make a voltage divider in the megaohm range and try again I suppose.
prc  320 psu replacement caps - Page 1
Forum section: electronics / repair

author: Jesset1996.5
author_rank: Regular Contributor
timestamp: March 26, 2016, 09:21:56 am
content: so my 1.7 and 2.2 uf caps are on the fritz and id like to replace them. i have looked online and there $20 which is a bit pricey for just one capacitor. could i just use electrolytic caps. if so what value. i cant seem to find the exact value so i have decided to ask on here since i know nothing about cap value yet.
HP 54542A  repair - Page 1
Forum section: electronics / repair

author: Daxxin
author_rank: Regular Contributor
timestamp: March 25, 2016, 05:00:08 am
content: Hi , need to replace this encoder , what model is this and can i buy replacement part online?

author: Testtech
author_rank: Regular Contributor
timestamp: March 25, 2016, 02:48:05 pm
content: I think it is an Alps Encoder, google the part number. If you can't find one, in other applications I have often used something similar, like one of the Bourns Encoders that will fit, that have similar characteristics.Is that encoder still working? If so, get some brass tubing that will just slip over the broken shaft and make a new shaft.
1996 ROWE CD JUKEBOX - Page 1
Forum section: electronics / repair

author: Seekonk
author_rank: Super Contributor
timestamp: March 24, 2016, 07:11:29 pm
content: A friend of mine picked up this CD jukebox. It worked for a little while giving freeplays and then stopped. It passed basic self test but had stored errors, low batteryvoltage. Figured I would start by replacing the 2325 3V lithium battery with a CR2025coin cell and battery holder. The board is spacious so I just pryed the spot weldsfrom the battery and soldered onto the shortened stubs leaving circuit board intact.An iron would easily fit under the battery holder with enough space to fit in the case.I've found the battery holders leads many times don't fit into the existing boardholes. Fired up the unit and it came up with a new checksum error. Cleared allerrors through front panel and then it powered up with no issues. Took a while, butfinally found the section in the manual to allow free plays. Pretty amazing thatthe CD mechanism still works on it . NOTE: Removing battery voltage will revert thehigher level passwords to 0000. This will have to be done even if the battery isgood to remove previous passwords.If you have one sitting in the basement and don't have a manual, the following mayhelp. I made this quick cheat sheet for future reference. This was a trip down memorylane. Remember when boards were this spacious? The connectors are poorly labeledso this plug identifier is included.1996 ROWE CD JUKEBOX 3/22/2016FAULT CODE PROCEDUREDoor switch in SERVICEDisplay...... ERROR HISTORYPress POPULARDisplay...... NO ERRORSOR...........Display...... ERRORS EXISTPress RESET & 0 together, then 80 POPULARDisplay...... A WARN 14-06 16 (batt voltage)Press RESET & 9 for next lineDisplay...... START 13:40 02/19Press RESET & 9 for next lineDisplay...... END 2:38 02/20See pages 5-15 for definitions of errors5-67 battery schematicClear errors see page 5-20SERVICEpress 0press 0enter 0000 (security mode)POPULARhold reset and press POPULAR twiceFREE CREDITS 2-24 2-29 3-11CONTINUOUS CREDITSERVICEpress 0 0000 POPULARRESET & POPULAR TWO TIMES55RESET & 9POPULARCENTRAL CONTROL COMPUTERP6 #1 is blue/whiteP5 #1 is orange/blackP4 #1 no connectorP3 #1 is redP2 #1 is redP1 #1 is redP15 #1 is red/whiteP14 #1 is purple UPP13 #1 is orange/black UPP12 #1 no connectorP11 #1 L to R white orange blankP10 #1 L to R white orange blankP8 #1 no connectorP9 #1 is greenBATTERY CR2025 RIGHT OF P6
Tektronix 2225 - Sweep length below minimum - Page 1
Forum section: electronics / repair

author: airlomba
author_rank: Contributor
timestamp: March 24, 2016, 11:20:15 am
content: Hello all,This is my first post in this great forum because I am too rookie to be of any assistance in the topics I have ben following and because I have in hands a Tektronix 2225 oscilloscope that I want to repair.So, the scope's problem is: the sweep length is below minimum. The scope's service manual states that the Sweep Length should be between 10.2 and 12 divisions. Well, at cold start, the length is just about 9.4 divisions, and after a run of about 4 hours at room temperature, the sweep length reaches almost 10 divisions (9,9), yet below the 10.2 divisions that correspond to the CRT width.To show you how it looks like, here is a picture taken after a cold start, where one can clearly see that the traces don't fulfill the screen:Anyone has already seen something like this? In accordance to the Service Manual, I need a Time-Mark Generator to be able to make adjustments in the Horizontal section of the scope. But I don't have such equipment. So I thank anyone who can point me some direction, make some comment or be of any help.Best regards,Emmanuel.

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 24, 2016, 12:14:35 pm
content: The fact that it changes while warming up points to one or more capacitors reaching end of life. However, you can probably simply adjust R775 to correct the problem for now. If you have any source with a known precise output check if the timebase is still correct.

author: airlomba
author_rank: Contributor
timestamp: March 24, 2016, 03:58:57 pm
content: Hello PA0PBZ,Thank you for your answer.Before I open the unit, I checked the Timebase using a function generator able to supply a 10 MHz reference signal. This signal's frequency was confirmed with another oscilloscope and it is correct.The timebase looks uncalibrated. Introducing the 10 MHz square wave in the CH1 scope input, one period of the signal spans across 7.8 (seven point eight) divisions only, using a 0.1us/div and x10 magnification in the Timebase.If I repeat the test applying 1 MHz signal to the scope, in order to disable the x10 magnification while maintaining a 0.1us/div, the period representation now spans across 8.8 (eight point eight) divisions.Unfortunately, I don't have the tools nor the time right now, to open the scope and tweak the R775 as you suggested. I'll have to do this next week.Meanwhile I'll read again the Horizontal chapter of the Service Manual and get familiar with the schematics.I'll post the results as I get them.Thank you for your help.Best regards,Emmanuel.
Help identify this IC: IL 1088EP1-03 - Page 1
Forum section: electronics / repair

author: 3Deye
author_rank: Contributor
timestamp: March 20, 2016, 12:26:24 pm
content: Hi,I am repairing a DC generator's voltage regulator and couldn't find the datasheet or a replacement part for this 8-Pin PDIP IC with the label:IL 1088EP1-03Will much appreciate your help.

author: chris_leyson
author_rank: Super Contributor
timestamp: March 20, 2016, 01:00:07 pm
content: It might be these guys,http://integral.by/eng/, check the logo.

author: wraper
author_rank: Unknown
timestamp: March 20, 2016, 01:09:09 pm
content: Photo please.

author: 3Deye
author_rank: Contributor
timestamp: March 20, 2016, 01:52:11 pm
content: @Chris, thank you so much. I contacted this company asking for more details since the IC is not mentioned on their website but most probably they are the manufacturer.From its connection in the circuit, I guess it's a PWM IC.@wraper, will try to post a photo soon, but anyways there is no logo on the IC, only the label I mentioned and nothing else.

author: 3Deye
author_rank: Contributor
timestamp: March 20, 2016, 03:36:23 pm
content: Wow! I found it in the spanish version of the website Chris pointed to:http://integral.by/spain/?section_id=59Its label is a bit different: KB1088EP1-03-4 but I think it's the IC I am looking for as it's defined on the website as: Driver of Power Bipolar Transistor for Hybrid Voltage Regulator for Alternator.After some more search I found its datasheet:http://www.bms.by/eng/spec/PDF/Kb1088EPe.pdfOk, now I am looking for an alternative IC that can do the same function. I would appreciate your help again!Thank you.

author: 3Deye
author_rank: Contributor
timestamp: March 23, 2016, 10:49:20 am
content: Still can't find an alternative for KB1088EP1-03. Can anybody help please?

author: wraper
author_rank: Unknown
timestamp: March 23, 2016, 11:43:26 am
content: This is Belarus special. This company likes to make illegal clones very much (they even make one of the FT232R clones, ftdigate tread here), so if there were any compatible ICs, they would be in the compatibility list over the link you posted.

author: 3Deye
author_rank: Contributor
timestamp: March 24, 2016, 01:51:29 pm
content: @wraper, Yes it has no compatible IC. Thank you for the info regarding this company.I think this can be an alternative: ST L9484http://www.st.com/web/en/resource/technical/document/datasheet/CD00003265.pdf
Schema of Yokogawa 701120 DL1300 Oscilloscope Power suplly - Page 1
Forum section: electronics / repair

author: Melgatronic
author_rank: Newbie
timestamp: March 24, 2016, 10:39:04 am
content: I´m a follower of EEV blog and I need the Schema of the power supply Yokogawa 701120 DL1300, a four channel vintage Oscilloscope. It makes a sound like the short circuit in secondary but I dont see which is the cause of possible overcurrent. The Supply Unit is a Nagano Japan Radio Co LTD model 3408. Please, thankyou, this is my first post.
DEAD GoPro hero 3+ black, 4 silver & black - Page 1
Forum section: electronics / repair

author: 1centchips
author_rank: Newbie
timestamp: March 22, 2016, 06:36:07 pm
content: I am in possession of new but out of warranty GoPros. All of them are like new cosmetic condition including the main board. All of them have not power. I have tried plugging into a charger with a good know battery. I have also followed all of the instructions listed on the gopro support website. I was hoping if I could revive them by microsoldering and replacing components. I did not find any schematics for these. Any help is appreciated!

author: Rasz
author_rank: Super Contributor
timestamp: March 23, 2016, 10:57:26 pm
content: well, start measuring then

author: SL4P
author_rank: Super Contributor
timestamp: March 24, 2016, 05:55:56 am
content: See if you can find out their history... were they returns, failed during warranty, power supply reversed etc.Then, since you're obviously inside already... connect the external supply, and chase the +v to see if it gets into the main board...SMT fuses, protection diodes... etcIf you don't know what these look like, then try posting some high quality images of the board - and if that fails possibly calling GoPro for an RMA number.

author: Seekonk
author_rank: Super Contributor
timestamp: March 24, 2016, 07:43:10 am
content: Simplest test is do they draw any power at all. No current would indicate something with regulator section.
Amprobe AM-160 - Faulty LCD Display - Page 1
Forum section: electronics / repair

author: Earfonia
author_rank: Newbie
timestamp: March 24, 2016, 07:00:00 am
content: Hi! I have an old Amprobe AM-160 (not AM-160-A), about more than 10 years old now, and the LCD display has aged, with some dead segments. The LCD has darkened, and looks pretty bad.I would like to ask, is there any place where I can buy the LCD display for this Amprobe AM-160?I guess probably similar part as for the AM-160-A, Brymen BM859A, or Extech MM570A LCD display? I just need the glass LCD display part for my AM-160.Any information is greatly appreciated!Thanks!
Iso-Tech (RS) ILCM 03 Earth leakage clampmeter DOA - schematic? - Page 1
Forum section: electronics / repair

author: FrankE
author_rank: Regular Contributor
timestamp: April 01, 2016, 05:58:08 am
content: http://uk.rs-online.com/web/p/clampmeters/4098972/Iso-tech make OEM meters exclusively for RS.Switch on ... nothing.There's a transistor looks like it's blown near where the battery jumpers go into the board. I suspect that's a good starting place. I can't make out any component markingsNo FXXX marked on the board to indicate fuse.No voltage measured at LCD terms, so it's probably not just a dead display.Scuffing on the cap between 4mm ports in the way of one of the PCB mounting screws indicates someone has been in this and not removed the 4mm terms before doing so to gain better access to the screws. I wonder if they took out the screw while the DUT was energised and blew the board.While I'm getting light and some glass ordered so I can see in the bloody thing does anyone have a service manual or schematic?Nothing on the interweb.
Hakko 850 hotair repair ? - Page 1
Forum section: electronics / repair

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: February 18, 2016, 04:45:53 pm
content: I picked up a used kinda working Hakko 850 hot air station and when working on the higher end - heat & air it seemed ok ,but when I was lower heat & air it would would overheat .I would guess that is should have a temp regulator - used some sensor feedback and is not working .I haven't looked , just assumed that getting a wring diagram / schematic may not be available , some suggestions on getting working again when using lower heat & air settings ?Thanks John

author: nanofrog
author_rank: Super Contributor
timestamp: February 18, 2016, 09:57:25 pm
content: Attached is a .pdf of the schematic for the Hakko 850B, 120V model (rather simple schematic built around a 555 timer & a upc1701c zero voltage switch).Hope this helps.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: February 18, 2016, 10:50:03 pm
content: ThanksI took apart & removed board to check for obvious issues , nothing found .Cleaned the points on the relay - I use dollar bills to rub on points .I forgot to mention that I was using one of the reducers , I have 4 sizes and was using the 2nd from the smallest on some SMD parts .It may have been working correctly , but too much heat & not enough air ?When I opened & inspected I operated with the reducer off , noticed that the heating element pulsed with the same frequency as the light next to the heater control , then as I adjusted from lowest to highest the frequency varied .I do not think there is a feedback to limit too much heat , only 3 wires one to case for ground , not enough for sensor / feedback .I have a copy of the Hakko , a Yoyue 850 that one of these days I should post some pictures to show where the copy cheaped out .

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: February 18, 2016, 10:58:01 pm
content: Messed up again , or the 1st time , noticed the diagram did not match my unit , then noticed that the diagram was for an 850B , and I did not note mine is the 850A model ;(

author: nerdalert
author_rank: Newbie
timestamp: March 22, 2016, 11:08:57 am
content: here is hakko 850 troubleshooting guide service manual

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: March 22, 2016, 01:29:12 pm
content: Thanks , my issue is not in the pdf , but good to have .I need to show some pictures of the 2 Hakko 850 and the Ayue , its obvious where the making cheaper happened .

author: nanofrog
author_rank: Super Contributor
timestamp: March 22, 2016, 04:51:02 pm
content: Quote from: KD0CAC John on March 22, 2016, 01:29:12 pmI think this would be really helpful.