hybridfree/eevblog-posts huggingface dataset:
Craft by Pace 25 SMT Soldering Station - Page 1
Forum section: electronics / repair

author: Johnny10
author_rank: Frequent Contributor
timestamp: November 19, 2015, 09:15:11 pm
content: I just picked one of these up and wondered if there are any manuals around?

author: Johnny10
author_rank: Frequent Contributor
timestamp: November 19, 2015, 09:40:16 pm
content: One similar to this.

author: miguelvp
author_rank: Super Contributor
timestamp: November 20, 2015, 02:36:44 am
content: Only thing I could find is this for US $25.00:http://www.exsupplies.com/pace-soldering-two-manuals-for-i136206/QuoteNot sure if they are still availableOtherwise you probably can contact Pace worldwide, but I can't find the manual on their site.https://www.paceworldwide.com/

author: Johnny10
author_rank: Frequent Contributor
timestamp: November 20, 2015, 04:21:52 am
content: Yes I wrote that site "exsupplies" couple of times.Waiting for response.There is one on ebay with the unit... wrote them about their manual.Guess I will have to wait and see !

author: miguelvp
author_rank: Super Contributor
timestamp: November 20, 2015, 04:39:34 am
content: It wont hurt to contact PACE as well:https://www.paceworldwide.com/contact-us

author: Johnny10
author_rank: Frequent Contributor
timestamp: November 20, 2015, 03:15:29 pm
content: Took your advice miguelvp sent a request to Pace last night.Just downloaded a scanned manual from Pace..Thanks Tony Jones!He acted very quickly to send a manual for a machine that has been discontinued way back in 1999.
UEI 393 broken jacks - Page 1
Forum section: electronics / repair

author: AKADriver
author_rank: Newbie
timestamp: November 07, 2015, 02:45:48 am
content: I bought a used UEI 393 multimeter on eBay for the grand sum of US$26.95! It was so cheap, as it turned out, because the common and V/R/C/temp jacks were broken on the inside!I've managed to solder across the breaks but I'm not confident that the repair will last for the long haul with probes being plugged and unplugged, stressing the joints. I'd like to replace the jacks themselves... but I'm hitting a wall. Can't find them on Digikey. Are these a proprietary part to "Finest" (which seems to be the supplier to UEI and Klein and others)?I sent a shot in the dark request to UEI to see if they'd offer parts, they obviously don't want you repairing things yourself though.

author: retiredcaps
author_rank: Super Contributor
timestamp: November 07, 2015, 04:38:49 am
content: Let's see a picture of your fix. Two clear focused pictures of each side of the pcb will help.

author: AKADriver
author_rank: Newbie
timestamp: November 07, 2015, 03:48:03 pm
content: I don't have a good macro camera, so if I can borrowratdude747's picture:The leads cracked at the red lines. The V/Ohm/Hz connector was easy to repair because it was already soldered there, and broken above the surface. The Com connector was broken inside and if I'm honest, looks a mess because the plastic started to melt. It's that one I'm more worried about.I can't find any part numbers on the plastic.

author: retiredcaps
author_rank: Super Contributor
timestamp: November 07, 2015, 07:48:45 pm
content: 5ky, a member here, bought some meters for his $50 shootout. One of them was the Klein MM2000 which is a rebranded Fine Instruments. He later shipped them to joeqsmith, another member here, for destructive testing.The MM2000 input jacks look identical to the UEI 393. Send joeqsmith a PM and ask him if he can desolder the COM input jack and mail it to you? He is just going to toss/recycle them afterwards. Maybe he can send you the other jacks as well for backup?

author: joeqsmith
author_rank: Super Contributor
timestamp: November 09, 2015, 03:29:33 am
content: PM sent.There were not a lot of good parts left on this meter. I removed the rotary switch, back light and the four connectors. If you like I could also send the case. It is damaged but the mechanics for the rotary switch are still fine. The rubber cover is fine.

author: joeqsmith
author_rank: Super Contributor
timestamp: November 20, 2015, 04:34:39 am
content: Did the parts I send you fit your meter?
Knight VTVM repair with video - Page 1
Forum section: electronics / repair

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: November 15, 2015, 09:59:27 pm
content: Just posted a little video I did about my repair of a Knight KG-620 Vacuum Tube Volt Meter.For the younger crowd, a VTVM is an analog meter that has a high impedance like a DMM. They are still commonly used for aligning radios and any other purpose where you would like to see the analog movement, but have very little effect on the circuit under test.This unit had some previous repairs that were kind of shoddy, and I wouldn't want to put the 1500V rated voltage through it, but it will be great for my uses.http://youtu.be/zq9SG5nOLmU

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: November 16, 2015, 12:52:01 am
content: I just couldn't help but leave the HP Nixie Tube counter running in the background

author: Radio Tech
author_rank: Frequent Contributor
timestamp: November 16, 2015, 11:25:51 am
content: Sounds interesting,Will surely check this out tonight. No YT at work.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: November 19, 2015, 07:39:53 am
content: Built up the VTVM probes from the kit I mention in the video, and they work great.

author: crispy_tofu
author_rank: Super Contributor
timestamp: November 19, 2015, 12:07:21 pm
content: Thanks for sharing, I really enjoyed it!Subscribed.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: November 20, 2015, 03:20:03 am
content: Glad you liked it. I am not advanced enough to film the whole process and show it. So instead I just try to recap the issues I had, etc.
Hantek DSO5102 CH1 issue and self calibration error x502 - Page 1
Forum section: electronics / repair

author: MarkM
author_rank: Regular Contributor
timestamp: November 19, 2015, 11:04:52 pm
content: I bought this scope quite awhile ago second hand, but I've barely used it. I noticed when testing today that CH1 reads about ~400mV higher than it should. CH2 reads correctly. I tried using other probes. Another issue is it won't self calibrate. I tried it after it was warmed up as well as when cold. No difference. It comes up with the x502 error.Google search comes up with people with the same issue, but no real solution. I haven't cracked it open yet to check it out, but I'll post up when I do. Any ideas for now would be greatly appreciated. It'll probably take me a few days to get to it.
Repair of a 8052 computer - Page 1
Forum section: electronics / repair

author: ChristofferB
author_rank: Frequent Contributor
timestamp: November 19, 2015, 01:04:46 pm
content: So I've bought this 8052 computer, and it worked briefly over serial (had some trouble, but I did get it working for a while). Today it does nothing. There's no life at all. No data, no clock, nothing.It's a fairly simple board with just the 8052 BASIC microcontroller, 2x 8255 ports, an EPROM, some sram, some misc. logic, a 74LS373 for data/address latching (I assume), and the MC1488/1489 rs232 line drivers.It requires 5V, + and - 12V and ground for power. I ran it on 5V only, and removed the 1488/89 (presumably the only parts needing the +-12V), and it did work in that config.I've reseated all socketed IC's, backed up the EPROM, 5V to all chips are good, but nothing moves.This could be because the clock doesn't do anything, but there's no real clock circuitry, just a crystal and some caps hooked up to the 8052. I've also tested all socketed logic and ram, works fine.I've measured noice, and there's about 0.2V Peak-Peak noise on the logic LO lines.What would the next logical move be?I fear that the 8052 has died, which would be a problem, they aren't that easy to come by.Any help would be much appreciated,Thanks in advance,-- Christoffer

author: ChristofferB
author_rank: Frequent Contributor
timestamp: November 19, 2015, 01:49:50 pm
content: Update: It most likely isn't the CPU. Just tried with another 8052 (non BASIC, as opposed to the processor used on the board) and it exhibited exactly the same behavior. Do crystals go bad? Never seen it happen, though.Unfortunately I don't have the schematics, only some random notes on overhead transparencies.--Christoffer

author: brabus
author_rank: Frequent Contributor
timestamp: November 19, 2015, 01:58:33 pm
content: Hello Christoffer,Do you have an oscilloscope? I assume yes, since you mentioned 0.2Vpp noise.Let's start with some basic stuff: is the RST line OK? Maybe the start-up reset (maybe just an RC) is stuck.If RST is OK, I would directly poke the crystal pins. Which 'scope do you have?Keep us updated! Good luck!

author: ChristofferB
author_rank: Frequent Contributor
timestamp: November 19, 2015, 02:10:17 pm
content: I found the trouble! some not-so-great soldering on the back of the board shorted some pins on the processorfixed now, and working great with a:*MCS-51(tm) BASIC V1.1*READY>Photo of the board attached. Pretty cool board, actually. Although who designs a single board computer without a reset button?Thanks for the help, anyway!--Christoffer
How to remove silicone-potted inductor - Page 1
Forum section: electronics / repair

author: eldis111
author_rank: Newbie
timestamp: November 19, 2015, 10:14:45 pm
content: I'm trying to rescue an inductor out of an aluminium case. It is partially potted in grey silicone (or something very similar to it). It has rubbery feel to it, but bonds to the inductor and case very strongly.Unfortunately the inductor is deep in the case, so there is no easy way to get in with a knife or tools. I know that there are some chemicals that can break down silicone to make it more brittle. The question is if they will not also damage the coating of the winding?Thanks for any tips!

author: ales22
author_rank: Contributor
timestamp: November 19, 2015, 11:32:31 pm
content: Usually the coating is very resistent to chemicals. It's not like some furniture varnish which you can wash off with a bit of thinner and it's quite a problem for soldering this "enamelled wires". I have special solder flux which attacks the coating, but only at high temperature. You may try some organic solvents like benzin or aceton, but if the case can be destroyed, I would use my Dremel (or BOSCH PWS 7-125) and carefully cut off the sides of that case. It looks quite big and solid, so it may be tedious work, because aluminium isn't the best metal for grinding.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 19, 2015, 11:36:17 pm
content: Concentrated nitric acid.**Warning: may dissolve the copper winding, and iron core, faster than doing anything at all to the potting. Also, rather nasty. Don't actually do this.Resins can usually be swelled with a nasty solvent, like methylene chloride, but that disrupts or swells or dissolves a whole lot of kinds of plastics and resins and such. So you might end up with clean wire... too clean.It does matter if it's actually silicone, or epoxy, or urethane, or polyester, or... any of a number of other possible resins. They've all got their flexible varieties, so it could be kind of anything just based on appearance.Why do you need to "rescue" it out of there? It looks quite happy where it is, and has a free heatsink besides!Tim

author: jwm_
author_rank: Frequent Contributor
timestamp: November 20, 2015, 12:03:22 am
content: If it is urethane based like shoo goop or e6000, the toluene will take it right off.

author: Kleinstein
author_rank: Super Contributor
timestamp: November 20, 2015, 09:48:36 am
content: If you don't need the case anymore, you could dissolve die aluminium in something like NaOH solution. Just don't use to high a concentration (might get to hot) and good ventialtion (produces hydrogen gas). The inductor should withstand NaOH.
Power supply EA-PS 9080-50 T - Page 1
Forum section: electronics / repair

author: Kopernik
author_rank: Contributor
timestamp: November 17, 2015, 10:45:19 am
content: HI!Does anybody have service manual for power supply EA-PS 9080-50 T ?I really need it, because it doesn't start up. The main relay it doesn't turn on.I check all power trasistors but, they are ok.. all caps looks OK.but the cuircuit is too large to look all elements and check them.so I don't know what to measure...Does anybody repair power supply like this?

author: oldway
author_rank: Super Contributor
timestamp: November 17, 2015, 12:31:33 pm
content: http://www.pewa.de/DATENBLATT/DBL_EA_EA-PS9080-50_ENGLISCH.PDFWithout schematics, knowledge and experience in repairing SMPS, it is dangerous to try repairing such a powerfull power supply.If you should have such knowledge, you would not ask such a question here.See 8.5 Demounting (p 13): !!Caution!! The unit can't be repaired by the user....Working on the open unit is allowed only for the trained electric engineer.
B&O Beomaster 1200 Problem - Page 1
Forum section: electronics / repair

author: officialrolfe
author_rank: Newbie
timestamp: November 15, 2015, 09:56:38 pm
content: Hi All, I have just acquired a Bang & Olufsen Beomaster 1200 Amplifier.I plugged in the Beomaster without understanding that the voltage selector was set to 110v instead of the UK's 240v.There was a slight flash from inside the Beomaster but am unaware of what may have fried. Any help would be greatly appreciated as I would love to get her running again.Regards,Ben

author: kc8apf
author_rank: Regular Contributor
timestamp: November 15, 2015, 10:38:29 pm
content: Looks like a schematic is available on elektrotanya:http://elektrotanya.com/bang_olufsen_beomaster_1200_sch.pdf/download.html. Hopefully the fuses blew quickly and nothing else got damaged. Start by disconnecting the power supply from all other boards, replacing the fuses, and seeing if the output rails are in spec.

author: mzacharias
author_rank: Frequent Contributor
timestamp: November 16, 2015, 01:27:18 pm
content: Normally the power transformer is the first casualty in this situation.

author: Seekonk
author_rank: Super Contributor
timestamp: November 16, 2015, 01:34:50 pm
content: After a certain voltage the transformer looks like a resistor. It is likely the fuse went before the transformer winding fused. Voltage to other components was likely limited to what they could stand.
NEED EEPROM DATA - HP6034 60V/10A Power Supply - Page 1
Forum section: electronics / repair

author: Peeps
author_rank: Contributor
timestamp: November 11, 2015, 02:57:15 am
content: I purchased a non working HP6034A power supply off eBay recently. It shows the symptoms of a kernal failure - all LEDs and display segments light up and stay lit upon power up. There's an amazing thread about ithere. The unit came with 2 replacement micro's (as it seems the seller found this thread) so I have a total of 3 and none of them make a difference. I replaced the memory with a pair of AM9112 256kb modules with no success.Perhaps it is an issue with the surrounding glue logic? I wanted to rule out the big 3 before going further with the repair.So if anyone has this supply and is willing to upload the EPROM data I would be happy to pay you for your efforts.

author: picburner
author_rank: Frequent Contributor
timestamp: November 13, 2015, 05:56:45 pm
content: The only place where I found the HP6034A eprom dump is here:https://github.com/bsdphk/PyReveng3/find/masterIt is in an abnormal format, used as example in Phyton, but with some patience maybe you can reconstruct the code...

author: Peeps
author_rank: Contributor
timestamp: November 15, 2015, 01:38:33 am
content: Woah I didn't expect a result so soon. Thank you! I will report back once I've had time to work this all out.
Fluke 87 (base model) worth it to repair? - Page 1
Forum section: electronics / repair

author: gooseEL34
author_rank: Regular Contributor
timestamp: November 14, 2015, 10:00:46 pm
content: Hey all-I am at the office so cannot snap a picture, but I have a Fluke 87 True RMS meter (not a III, IV, V but the base model).The female banana input jack surround has broken. The jack still works and I am wondering if it needs to be fixed, from what I can tell, the plastic above the actual metal contact of the jack serves to stop you from pushing the banana plug too far into the unit and doing damage. I suppose it is there to stop accidental arcing if those ends of your leads wiggled out, but can anyone posit why I should fix it if the unit otherwise works perfectly?? ThanksTimOh...I mainly use it to test 300-450 volt DC voltages in tube amps and sometimes mA of current as well. I have it and a 187. Is there anything the 87 does better than the 187. I am thinking of liquidating one of them.

author: retiredcaps
author_rank: Super Contributor
timestamp: November 14, 2015, 10:20:18 pm
content: Quote from: gooseEL34 on November 14, 2015, 10:00:46 pmModemhead's DIY repair blog for the above problem.http://mrmodemhead.com/blog/fluke-banana-jack-repair/

author: retiredcaps
author_rank: Super Contributor
timestamp: November 14, 2015, 10:29:02 pm
content: Quote from: gooseEL34 on November 14, 2015, 10:00:46 pmIf it were me and I could only have one, I would choose the 187.Pros of 187 vs 87- 50,000 count vs 20,000 count- 50,000 count is 4 update/sec vs 20,000 is 1 update/sec- dual display vs single display- temperature vs none- capacitance reading up to 50mF vs 5uF- dBm- setup menu for various options like backlight timeout, power off, etc vs noneCons of 187 vs 87- 72 hour battery life using 4 AA vs 500 hours using 9V- 187 is bigger and bulkier than 87- no service manual and schematics for 187

author: gooseEL34
author_rank: Regular Contributor
timestamp: November 14, 2015, 10:45:54 pm
content: Thanks for the two replies above. EXACTLY what I was seeking!This forum rocks!
help help,need the keithley 263 calibrator ROM for repair - Page 1
Forum section: electronics / repair

author: chinapp
author_rank: Contributor
timestamp: November 09, 2015, 08:51:46 am
content: Just got a keithley 263 calibrator ,not very good,can not power on, aftere several days check, i believe the ROM was corrupted,does anyone can help me to give a copy of this ROM,the ROM IC is U47, A "AM27C128 " 16K*8 ROM IC,which signed "263-800 A1"almost any programmer can read this IC,you can just send me a copy of the file to email :gavin_pro "at" 163.comthanks for any kindly suggestion!

author: chinapp
author_rank: Contributor
timestamp: November 20, 2015, 08:08:28 pm
content: seems no one give a hand

author: TiN
author_rank: Super Contributor
timestamp: November 20, 2015, 08:24:38 pm
content: Don't have it, sorry.Did you try to read your ROM?
Hard wiring a baby monitor remote - Page 1
Forum section: electronics / repair

author: mzac
author_rank: Newbie
timestamp: November 12, 2015, 12:10:56 am
content: Hi, I have a Philips DECT baby monitor that I purchased about 5 years ago. Of course the batteries have failed in the remote/parent unit so I tried changing those a few months ago and now they're dead as I was always leaving it on the base turned on.So that's what I want to do, have it hard wired and on all the time. It normally takes 2 x AAA batteries so I tried to figure out the best way to power it. I took a chance and gave it 5V from a usb connection and low and behold it works, no smoke!The problem I'm having now is that this unit has some kind of low battery detection and at 3am this morning it started beeping like crazy saying the battery was dying. There is no way to disable the beeping!So my question to all of you is how could this unit be figuring out it has a dead battery and what can I do to fool it? Is it checking resistance, capacitance? Can I just put on of those across the battery terminal in line with my 5VDC alligator clips?The model I'm using is a Philips SCD520, FCC ID is BOUSCD520HThanks in advance!

author: mzac
author_rank: Newbie
timestamp: November 12, 2015, 11:19:25 pm
content: Anyone?

author: nidlaX
author_rank: Frequent Contributor
timestamp: November 12, 2015, 11:33:08 pm
content: How did you wire it up and for how long was it working before this problem started? It's possible that there's a discrete battery charge/discharge controller chip inside that monitors the battery voltage. If you damaged the chip/circuit with an over-voltage, it could be malfunctioning. Maybe the microcontroller is receiving no battery voltage signal, so it thinks the battery is dying/dead.I think your best bet would be to take it apart and start tracing out the battery input circuitry and see if anything has failed. 5V into a nominal 3V input might not have let out the magic smoke, but that doesn't mean the device was designed to tolerate such an over-voltage for long periods.

author: retiredcaps
author_rank: Super Contributor
timestamp: November 13, 2015, 01:43:44 am
content: Clear focused pictures of the pcb (both sides) would help. Focused enough so we can read the writing on the chip, resistors, etc.

author: mzac
author_rank: Newbie
timestamp: November 14, 2015, 02:59:17 pm
content: Hi, thanks for the feedback. I took it apart and took some pictures, the last picture shows what looks like to be a bit of burned components, but not too sure...
FLIR InfraCAM - Blank Screen - Page 1
Forum section: electronics / repair

author: Chanc3
author_rank: Frequent Contributor
timestamp: November 10, 2015, 01:45:44 pm
content: Good afternoon EveryoneI've been given an old FLIR InfraCAM, which doesn't currently work. When powered on, the splash screen is displayed, then I get a blank screen, like it hasn't loaded anything. I've tried connected it to my PC and either telneting into it, or FTP, but alas it doesn't connect - but it does detect it has been connected to the PC via the audible "der dum".I've opened it up and had a look, but I cannot seem to see any loose connects etc, but it does look like it has got wet in the past...Any ideas?

author: Chanc3
author_rank: Frequent Contributor
timestamp: November 13, 2015, 04:12:41 pm
content: Anyone? I'm not sure how much further I can progress with this - maybe I just need to sell it on...

author: crispy_tofu
author_rank: Super Contributor
timestamp: November 14, 2015, 10:07:06 am
content: Can you provide clear pictures of the inside of the camera?
Tek305 Multimeter Repair: OHMS - Page 1
Forum section: electronics / repair

author: Martin.M
author_rank: Frequent Contributor
timestamp: November 14, 2015, 07:22:28 am
content: hello friends,I have the following problem:The internal multimeter in my SONY-Tek305DMM (this is a fully seperated board with own DCDC to be full isolated) have a problem when testing OHMs.AC, DC is allready working.Description: When testing R, it star like counting, after a longer time it stop at the right resistance.100k: longer time to be right10k: short time to be rightzero Ohms: longer time.Videos to watch that directly,attention large files around 14MB:testing a 100k.http://www.wellenkino.de/305/v1.avipicture from the stop:testing a 10k.http://www.wellenkino.de/305/v2.avitesting with shorted cables:http://www.wellenkino.de/305/v3.avithe service manual is here:http://www.wellenkino.de/305DMM/305DMM.pdf(!! 25MB)I think the current source with the Fet and the OP will make that problem. Good tips are needet.greetingsMartin
kw-avx720 jvc black screen problem - Page 1
Forum section: electronics / repair

author: steliosssssss
author_rank: Newbie
timestamp: November 12, 2015, 01:32:04 pm
content: hi!ihave a kw-avx720 car head unit and i have this problem:when i push the power button the buzzer sound like when its power up the dvd is spinning but nothing else....the screen doesnt show anything and the unit doesnt do anything else!can someone help me and guide me to solve the problem?thanks for your time
HP 8568a input level low. - Page 1
Forum section: electronics / repair

author: Simon Spiers
author_rank: Regular Contributor
timestamp: November 11, 2015, 05:55:58 pm
content: Hi everyone, wonder if the experts can help with a little problem.Work have finally scraped the HP8568a SA after the power supply blew up a few years ago, so it came home with me.After replacing a shorted capacitor on the PSU the thing seemed to work fine.However when running calibration I can't get the -10dB level high enough for the calibration to continue and it stops with message adjust attenuator input.I have run the various self calibration tests and none complete.It looks to me as if the input has lost gain, or maybe the limiter has failed?The attenuator looks like it's OK despite my first thoughts otherwise.Any help would be gratefully appreciated.Here's the result

author: cncjerry
author_rank: Unknown
timestamp: November 11, 2015, 09:17:10 pm
content: Put a known signal into the SA and post the results. Or measure your calibration signal output on a scope into 50ohms.Also, check the selection relay for the two inputs buy putting the signal into both to make sure the relay is working properly. I have one that has a problem with the relay and I have to punch it several times to get the right level.A lot of the 8568a/b analyzers have blow inputs.

author: MadTux
author_rank: Frequent Contributor
timestamp: November 11, 2015, 09:36:16 pm
content: If different step attenuator settings don't change the level displayed, chances are high that either the AC/DC input selector relay is broken (in front of attenuator) or that something further in is toasted.You might do a sweep from a few Mhz to 1.5GHz and see whether that changes anything (level should get progressively better if input selector relay is dead, since impedance of broken relay (capacitive coupling) decreases with higher freq. 8568 has a coax RF limiter diode in front of input. It probably gets fried first, if input is overloaded. Remove it and see whether it changes anything, but install new one if it's broken before use, so the front end mixer lives longer. I have bought and rebuild a few 8568s and none had a broken input mixer.BTW, if you dial in 0dB into attenuator setting, you can basically remove any attenuator elements from the equation.Also that noise free baseline IMO doesn't look promising.Didn't see you are in 1db/div, so that is normal

author: cncjerry
author_rank: Unknown
timestamp: November 11, 2015, 09:49:41 pm
content: yes, just watched the video and agree with MadTux. That noise baseline looks like way too low.

author: Simon Spiers
author_rank: Regular Contributor
timestamp: November 12, 2015, 08:19:25 am
content: Thank you all for your input and time.I have resolved the problem.The problem was me really.The link lead I was using was a scope lead designed to be used on a 1 meg input.The lead is resistive and as a result makes a great attenuator when fed into 50 ohms!Sorry everyone!
Dell 2210 LCD displays - Page 1
Forum section: electronics / repair

author: casinada
author_rank: Frequent Contributor
timestamp: November 04, 2015, 12:09:02 am
content: I have a few Dell 2210 that have the same problem, They are too bright on the right side of the screen. I tested the fluorescent lamps and they work, I removed the capacitors of the digital board and tested them, and replaced them. I also tested and replaced the Capacitors on the power supply. Has anybody come across the same Problem? The LCD is an LG LM220E1(TL)(P4)Any help would be greatly appreciated. It would suck to take these displays to the dump.

author: Rasz
author_rank: Super Contributor
timestamp: November 04, 2015, 02:42:32 am
content: I dont think thats backlight, black monitor still has full backlight on, light is blocked by the lcd itself

author: olewales
author_rank: Regular Contributor
timestamp: November 04, 2015, 09:57:27 pm
content: Quote from: Rasz on November 04, 2015, 02:42:32 amI second that. Seeing that darker strip on the right side of the display my first guess would be moisture in the LCD itself. Maybe layers from which the panel is constructed (polarization films, etc) are separating? Does the image change when you press gently on the display?

author: Rasz
author_rank: Super Contributor
timestamp: November 04, 2015, 11:03:10 pm
content: I didnt even notice that darker strip :0 wanted to write bias voltage, but its rounded! it does look like something unglued/separated

author: casinada
author_rank: Frequent Contributor
timestamp: November 04, 2015, 11:39:43 pm
content: My pictures are terrible, I admit but there is no humidity here in Arizona. If anything, it is extremely dry. The extra brightness is green in color. I will try to take a picture of the screen when is connected to a computer. These particular monitors fail way too soon. I was able to repair a couple with different problems and they come from different customers. I have 5 in my garage with this problemThank you

author: olewales
author_rank: Regular Contributor
timestamp: November 05, 2015, 12:57:31 am
content: Quote from: casinada on November 04, 2015, 11:39:43 pmDid all of them get this green tint in the same area?

author: casinada
author_rank: Frequent Contributor
timestamp: November 05, 2015, 03:47:12 pm
content: yes, they all are failing the same way.

author: Rasz
author_rank: Super Contributor
timestamp: November 07, 2015, 11:47:48 am
content: is it still green on white background?even bad lamp wouldnt shine thru blacked out lcd, so I guess those TN panels are pretty shit

author: Rasz
author_rank: Super Contributor
timestamp: November 11, 2015, 06:00:01 pm
content: might be just degradation due to temperature - led strip is on right sidelike here:
Sourcing this Part metal oxide Varistor ZNRFK691 63 - Page 1
Forum section: electronics / repair

author: R_G_B_
author_rank: Frequent Contributor
timestamp: November 16, 2015, 08:41:54 pm
content: can anyone help me source this part or its equivalent its for the input surge protection of a multimeter:metal oxide Varistor ZNRFK691 63farnell don't have it.Thanks for your help.R_G_b_

author: helius
author_rank: Super Contributor
timestamp: November 16, 2015, 09:03:24 pm
content: What is the clamping voltage? 63V?

author: R_G_B_
author_rank: Frequent Contributor
timestamp: November 16, 2015, 09:14:15 pm
content: clamping voltage is 650V max.the equivalenthttp://www.farnell.com/datasheets/652569.pdfbut farnell don't sell this one: ERZVF2M391 which is the one I needed i think?thankR_G_B

author: R_G_B_
author_rank: Frequent Contributor
timestamp: November 16, 2015, 10:02:38 pm
content: Parts found and Ordered from RS.ThanksR_G_B
Simple way to test fire this driver chip?   - Page 1
Forum section: electronics / repair

author: viper
author_rank: Regular Contributor
timestamp: November 10, 2015, 06:05:23 am
content: Doing a repair and suspecting the attached chip to be bad. Due to the level of difficulty to even get to the chip by desoldering a double stack of boards, I really need to know if it is bad.The way it was connected in circuit are as such.Vcc - pins 1,6, are connected directly to the source 12V power provided through a pin connector. There is no protection on those pins.GND - pin 2, there is a paralleled diode and 10K resistor to ground, same as examples in data sheets.CS-DIS - pin 5 has a 10k resistor to groundInput - pin 3 hsa a 10K series resistor going back to an MCU output legCurrent sense - pin 4 has a 10k series resistor going back to another MCU pin.I am really not familiar with the chip or its internals and only need to determine if it works or not. Probably easier to test a known good one first but.....I need to know what voltages, resistors, etc I might use to give it a quick test. I don't plan to run much if any real load off the chip but I guess a simple 12V load would be easy. I really do not understand the input and current sense difference and use. I figured this was more or less a FET in which the MCU is just operating the gate. There seems to be more to this chip.

author: Psi
author_rank: Super Contributor
timestamp: November 10, 2015, 08:09:40 am
content: The VN5 chips are very hard to blow up.They are protected from shorts/temp/reverse polarity etc.With..12V on pins 1,6CS-DIS 10k to GNDCurrent sense ~2k to GNDAnd a load connected between OUTPUT and GND (lamp or something, it needs to draw some current)You should be able to switch the load on/off with a logic level signal onto the input pin.If it overtemps/shorts/or the load goes opencircuit it will go into fault mode and the voltage across the current sense resistor res will jump up.

author: viper
author_rank: Regular Contributor
timestamp: November 10, 2015, 09:12:33 pm
content: I think I have decided to just replace the chip as I really need a known good one to test against anyway and if I fry the old one on the bench, the test was be null anyway.But, to expand on my issues, somehow a desoldered diode has escaped! I do have the markings but having trouble ensuring the right replacement.Marking was "A4" with a sideways 7 at the end. Looking up specs, it looks like this could be a schottky... or not...?
DVD Player Power Supply Repair - Page 1
Forum section: electronics / repair

author: fusekiller
author_rank: Newbie
timestamp: November 10, 2015, 11:57:36 am
content: Hi,I try to repair this power supply of a DVD player. The +12v rail measures 8.5V, the -12V rail is -9V both with no ripple. All other voltages are ok.I checked the filter caps with an ESR meter but they all seem ok.What can I try next? I have no schematics and btw. I am not a switch mode power supply expert.Thanks for any help!

author: Srbel
author_rank: Frequent Contributor
timestamp: November 10, 2015, 02:19:32 pm
content: Check if the voltage reference is giving the correct voltage and if feedback ressistors are of correct ressistance.

author: grumpydoc
author_rank: Super Contributor
timestamp: November 10, 2015, 02:53:17 pm
content: The chances are that the circuit is not a million miles from this:Which I found by googling for 5LO380R application notes/datasheets/circuits - your board doesn't have any linear regs on the secondary side though so just ignore the stuff to the right of the vertical line through C18, C19, C20, C21 and C22.The regulation will just be picked up from one of the rails - probably 5V so that only really leaves the very few secondary side components in the +/- 12V rails to be a problem.That's IF the PSU is the problem - have you checked whether feeding in +/- 12V makes the player work?

author: fusekiller
author_rank: Newbie
timestamp: November 10, 2015, 04:21:32 pm
content: Quote from: grumpydoc on November 10, 2015, 02:53:17 pmGood point! I powered the DVD drive from an external supply and it still did not accept any disk. The I tried a PC drive I had lying around and now the player works, even with the internal power supply which I suspected to be faulty.The display becomes significantly dimmer every time when the drive (even the original one) draws current. So maybe the PSU is not 100% ok, but it does the job.In the next step I'll try to adjust the pots on the laser unit which I have sucsessfully done several times before.Thanks everyone for the hints, I will keep them in mind for the future!
SMPS repair Astec MP4-1N-1N-4EE - Page 1
Forum section: electronics / repair

author: tonyh88
author_rank: Regular Contributor
timestamp: November 09, 2015, 09:45:52 pm
content: Hi ,I'm repairing an older modular SMPS at the moment from the ASTEC company whic is now known as Artesyn Embedded Technologies.The SMPS is a modular rack with 2 slot occupied with single output 15V DC units and 1 slot occupied with a +5V dual output.I'm not an SMPS expert but I think it is using a kind of half bridge topology. The module itself converts 380VDC that was rectified and boosted from the 120VAC in the main rack to the required DC output (5V in my case).The +5V module is dead, no output. I checked the usual ( output diodes, filter caps, switching mosfets, bridge rectifier .....)I narrowed down the problem to the Pwm controller. The pwm controller is UC2825DW from TI. There is no output waveform on the controller. Vref is good at 5.1V and vcc is good at 17V.What I don't get is that while troubleshooting, I accidently shorted pin 14 which is OUTB of the smps to VCC and the supply started. I confirmed this multiple time. If I force a voltage on the output pins of the pwm controller the switching action will start and the power supply works just fine.What I don't understand is why is this so and what could be the problem? A bad component in the start up circuit locking the controller? A bad chip? I have two of these broken SMPS with exactly the same behavior.Any ideas or help would be welcome. It is a complex PSU and I don't understand all the circuits for now.Thanks

author: voltz
author_rank: Frequent Contributor
timestamp: November 09, 2015, 11:09:25 pm
content: Hi,Since pins 11 and 14; AOut and BOut are the actual drive outputs presumably to some switching device, then the power needed to get that output stage started ie. Pin13 VC may be missing. So temporarily pulling BOut high could be starting the process without VC. So.. is Vc missing? If there is voltage at that pin, then the chip itself may be dead and Vc is internally disconnected. A lot of guesswork there..

author: tonyh88
author_rank: Regular Contributor
timestamp: November 10, 2015, 03:00:42 am
content: Yes lot of guessing.... There is voltage (17V) on the VC pin 13. The outputs of the controller switch a pulse transformer which then drives the 2 mosfet alternately if I understand the layout correctly.Maybe I'll try replacing the chip since I can get them fairly cheap from digikey. Looking at it under the microscope there might be a blow hole on one of the capacitor on pin 3 on both of the devices so I will check that first.I could always replace the PSU but since we have 2 of them with the same problem we would like to find the culprit. For some reason It's not easy to find PSU with 2 15V outputs and 2 5Volt outputs without going in custom expensive PSU.Thanks for the help.I do have some photo that I could upload if anyone has an idea.
Chasing my tail to find ground circuit for this chip... - Page 1
Forum section: electronics / repair

author: viper
author_rank: Regular Contributor
timestamp: November 09, 2015, 04:34:50 pm
content: So I am working on a Ford Body Control Module. The vehicle was in an accident and wire harness was smashed so some shorts occurred. the ECM also took a hit to the 5V power supply chip for the sensors but I was able to find and replace that chip. Now I have issues with the BCM. The rear hatch will not open for any reason and per the vehicle schematics, the latch relay is driven by the chip I linked. As was my 5V ECM chip, this one seems rather well protected BUT there is some indication that reversed polarity could damage the chip so there is a diode and resistor to ground.I have found the chip on the BCM board and already desoldered it via hot air but the main issue is although I have found the pin on the MCU that drives the chip, I cannot find the ground at all! As you can imagine, these boards are production, 1x use kinda thing. Throw aways. So they were not really meant to be repaired. There are hundreds of vias and this is a tri-level board. I see the ground going to a 10K resistor, then looping back to the CS-DIS and that trace pops into the center layer with a via and I have no idea where it surfaces! I have spent hours testing everything and almost convinced at this point the trace may be burned BUT when I throw the meter in auto ohms, it seems to talk to several things from 10-100K ohms. If the trace was really blown, would it show up somehow visually?I started combing the board for anything resembling a diode as I am expecting to find a diode and resistor to ground. At this point I cannot even determine what ground is! It is a complex critter!

author: viper
author_rank: Regular Contributor
timestamp: November 09, 2015, 07:35:32 pm
content: Never mind. I found the mysterious ground. Looking at the some traces wrong. Hate when they make odd turns right under a component...I am currently torn in what to do though. components to ground are fine, input protection devices to the VN5016 are all intact, and I am not finding anything obvious on the chip to indicate it is toast.Does someone have an idea, in an automotive app, what might cause this chip to fail in a large network of other components and all others seem to work fine? This chip drives the coil of a small relay that is in the fuse panel under the hood. However, it sure looks like you could run 12V back to the chip all day without concerns. It also handles way more than 12V. Not too convinced yet that I have my smoking gun.
465B+DM44 repair - Page 1
Forum section: electronics / repair

author: onesixright
author_rank: Frequent Contributor
timestamp: November 10, 2015, 05:39:51 pm
content: Hi All,I got my first vintage TEK 465B scope. What i tested only few buttons are not working fully.- Top (DM44) the time button is broken.- Left side CH2, the red var button. Although it works, it doesn't want to 'click' in CAL mode.- Top right B trigger inner knop (+/-) doesn't work.Any ideas for spare parts ?

author: PaulAm
author_rank: Frequent Contributor
timestamp: November 10, 2015, 07:34:26 pm
content: The detent on the Var knob does not always click on these scopes. If the uncal light goes off and it works properly, just leave it.Is the B trigger source in Norm? The B +/- knob or B trigger level have no effect if its in "starts after delay" mode.The only place I know of to get buttons for the dm44 is a parts donor.

author: onesixright
author_rank: Frequent Contributor
timestamp: November 10, 2015, 07:42:05 pm
content: Hi Paul,I checked the var, but the light doesn't go off. The B trigger +/- switch, is mechanical stuck. It doesn't want to move and I don't want to force it.Yeah, i guess i need to find a broker one.Thanks!

author: mtdoc
author_rank: Super Contributor
timestamp: November 10, 2015, 07:43:00 pm
content: Quote from: onesixrightThe best source for used Tek scope parts that I'm aware of isHEREAnother option is to buy a non-functioning " donor scope" from eBay.

author: PaulAm
author_rank: Frequent Contributor
timestamp: November 10, 2015, 09:18:34 pm
content: OK, looks like you might need some parts. QService in Greece is a good supplier and might be a little easier than Sphere for you. You'll need to get a service manual and look up the part numbers. I think you can find a 465B manual on the net for free, the DMxx manuals are hard to find. You might want to try Artek for that one. I have a DM44 operator's manual, but not a service manual.Once you get the part number, you can try googling it, something might show up.You still might need a parts donor. Annoyingly, small parts like knobs and switches, which get the most abuse, are about the hardest to source.
Siemens PLC programmer keyboard - Page 1
Forum section: electronics / repair

author: EMUD
author_rank: Regular Contributor
timestamp: November 04, 2015, 02:29:08 pm
content: Hi,I have two plc programmers for Siemens plcs. These are very rugged PCs with special interfaces and a special keyboard. Now both keyboards are down. They are foils with silver printed conductors on it. The controller was glued and has separated itself from the foil.Has anyone repaired something like that and could help me with his experience?

author: olewales
author_rank: Regular Contributor
timestamp: November 04, 2015, 09:36:54 pm
content: Subscribing to this thread. I had similar problem recently with LCD flex cable that was was originally glued to the PCB but broke off. I was eventually able to improvise a "press fit" between PCB and the cable but that obviously won't work in every case. Is there a "proper" way for fixing those? electrically conductive glue? How do you apply it to prevent bridges between tracks?

author: mich41
author_rank: Regular Contributor
timestamp: November 08, 2015, 01:26:13 pm
content: I once fixed a keyboard membrane by soldering jumper wires to it, but I would never want to do that again.Check if this "special interface" isn't just PS/2 with weird plugs. How old and how PC-compatible are these machines?

author: amyk
author_rank: Super Contributor
timestamp: November 08, 2015, 02:00:33 pm
content: https://en.wikipedia.org/wiki/Anisotropic_conductive_film3M 9703 is apparently one very popular type of this. A roll is pretty expensive but you can find it being sold in small quantities too - "iPod/iPhone repair tape" seems to be what they call it.

author: zoltan
author_rank: Contributor
timestamp: November 08, 2015, 07:08:50 pm
content: Quote from: amyk on November 08, 2015, 02:00:33 pmThat's the real thing. Used it before, just have to press well for good conductivity.Sold on ebay as "Double sided vertical Conductive tape", "conductive z-axis tape", ... under US$10 for 10 cm.
Mouse rotary encoder [Mad Catz MMO 7] - Page 1
Forum section: electronics / repair

author: TomTomminson
author_rank: Newbie
timestamp: August 21, 2015, 06:55:16 am
content: Hi guys,do you know where I can find a rotary encoder like this for my mouse?Here some other pictures of the product:http://www.overclockers.com/forums/showthread.php/753083-Fixing-Mad-Catz-M-M-O-7-double-click-issue-DIYThank you!

author: Rasz
author_rank: Super Contributor
timestamp: August 21, 2015, 03:20:34 pm
content: alps makes this type of encoders

author: Gyro
author_rank: Super Contributor
timestamp: August 21, 2015, 09:19:42 pm
content: Silly as it may seem, another mouse?.... An old Genius optical mouse uses this type of mechanical encoder, if you can find one. One that looks like this:Edit: A PS2 onehttp://www.penguinunitedforum.com/viewtopic.php?f=3&t=5287You could also try removing it and cleaning the contacts.

author: TomTomminson
author_rank: Newbie
timestamp: August 22, 2015, 04:54:25 am
content: Quote from: Rasz on August 21, 2015, 03:20:34 pmYes, thank you! the seems to be the right place! Now I've to find a dealer.QuoteThank you too! It's not silly, for the click button, in example, I've used another mouse couse most of good mice use an Omron micro switch.But rotary encoder may be very different from one to another, at least in dimensions and pin configuration. I'll try to look for in every mouse I open.QuoteI'll do it of course, but first I need a replacement, couse it's so small and something can always go wrong.Thank you all for answers!

author: rvalente
author_rank: Frequent Contributor
timestamp: August 22, 2015, 03:05:08 pm
content: Does he still makes the characteristics rotating noise? Maybe the spring broke...Have you tried to spray some contact cleaner? You may have a mix of dirty, oxide, sweat and fat grease inside...Some rubbing alcohol (isopropanol) may helps to..

author: Gyro
author_rank: Super Contributor
timestamp: August 22, 2015, 04:00:04 pm
content: I was going to suggest some IPA too but I couldn't think of a polite way of describing the possible contents of the encoder, that you have managed to do so well

author: TomTomminson
author_rank: Newbie
timestamp: August 24, 2015, 06:28:27 am
content: Quote from: rvalente on August 22, 2015, 03:05:08 pmNope, the problem wasn't the noise. It's like you scroll down on the page and, on a random number of scroll, it scrolls up for one or two steps. Or viceversa. It was very annoying!I've cleaned with alcohol and now seems to be all right! But, you know, it's better have a replacement in home if this component is a trouble one.I haven't find yet the same exact model of rotatary encoder that is now in the mice.Thank you all!

author: TomTomminson
author_rank: Newbie
timestamp: November 07, 2015, 05:59:42 am
content: After searching, buyng and comparing... as you said in the first answer, this is the boy:http://www.alps.com/prod/info/E/HTML/Encoder/Incremental/EC10E/EC10E1220501.html#PhotoThank you all!

author: Gyro
author_rank: Super Contributor
timestamp: November 08, 2015, 02:12:13 pm
content: Good of you to come back and let us know!Far too many threads die open-ended.