hybridfree/eevblog-posts huggingface dataset:
Yamaha RXV477 in DC protect - Page 1
Forum section: electronics / repair

author: vboss5764
author_rank: Newbie
timestamp: September 06, 2022, 05:04:43 pm
content: I just repaired this stereo FR channel, still saying "DC protect 255H" I measure about -9 volts to ground on all emitters, collectors of the mains, on all the big emitter resistor pins. I have checked all the channels, everything looks fine, no bad components in the channels, seems to be back feeding from the DC protect line. Its on every channel too. I pulled all the main outputs and still have the voltage. Im stumped, I have spent too many hours chasing this ghost.

author: shakalnokturn
author_rank: Super Contributor
timestamp: September 06, 2022, 09:07:03 pm
content: What was the repair about? Initial symptoms? Parts replaced and where were they bought?If you're sure enough the DC offset comes from the DC protection circuit, surely you can lift a component to confirm that.

author: wasedadoc
author_rank: Super Contributor
timestamp: September 06, 2022, 09:44:37 pm
content: Some years ago I repaired a Yamaha AV receiver that was shutting down just after power on with a diagnostic message about voltage. Turned out nothing amiss with the power amps. A 5 Volt regulator for some of the ancilliary circuitry had failed and its voltage was also incorporated into the power amps protection sensing.

author: vboss5764
author_rank: Newbie
timestamp: April 23, 2025, 03:11:02 pm
content: I know this is old but I just stumbled on it again so update... so the problem was simple, one of the ribbon cables was installed reversed, these cables only have contacts on one side, so the contacts were on the wrong side, stupid mistake, blame my old eyes, its been working great since.
Yamaha RXV663 - Page 1
Forum section: electronics / repair

author: geobee
author_rank: Contributor
timestamp: January 31, 2021, 11:13:13 pm
content: Hi all, this came onto the bench dead. Replaced the usual suspect, the 22Nf cap in the supply. Still no joy, on checking there is no 5 volt supply, lifted the secondary of the standby transformer, and the ac came back up, but in circuit something is loading it down. Checked several components downstream, but cannot point the finger at anything in particular. I have repaired many Yamaha amps, but this one is becoming a real challenge. Any ideas to check would be great. Cheers.

author: mzacharias
author_rank: Frequent Contributor
timestamp: February 02, 2021, 04:56:13 pm
content: Yamaha green power supply analysis

author: mzacharias
author_rank: Frequent Contributor
timestamp: February 02, 2021, 05:08:11 pm
content: waveforms
Yamaha TX-400U Tuner station memory not working. - Page 1
Forum section: electronics / repair

author: Paceguy
author_rank: Regular Contributor
timestamp: August 02, 2022, 02:21:09 pm
content: I have a Yamaha TX-400U tuner that I listen to a few times per week. Recently, it stopped holding the stations that I programmed into it's program memory. When power on, it is not on the station it was on when last turned off. Most of the time it is at 1010 AM when first powered up. I don't see a battery, what cap could be faulty?

author: KevinA
author_rank: Regular Contributor
timestamp: August 02, 2022, 06:17:14 pm
content: Backup "battery" is C143, 4.7 farad 5.5V capacitor

author: Paceguy
author_rank: Regular Contributor
timestamp: August 02, 2022, 07:27:04 pm
content: Is it a 4.7Farad or .047Farad cap? I found the manual online and it is C143 which they list as 47000uf 5.5 volt.
Yaskawa CIMR-04AS3 Inverter for CNC - Page 1
Forum section: electronics / repair

author: Spikee
author_rank: Frequent Contributor
timestamp: January 16, 2024, 11:29:30 pm
content: Hi all,I recently bought a used CNC machine for the hobby which came with a known fault being an issue with the ATC.So far i have figured out that the issue lies in the inverter (it goes into fault mode number 5). Unfortunately, there are no schematics available for this Junspeed S300 inverter.When I inspected the PCB i saw that two traces were missing and that resistor R2 was broken. I fixed this (also renewed the big capacitors) but when plugging it in again R2 resistor burned out immediately.Note traces have been repaired at the red circle. ; the control board mounts on thisControl board:I have deducted the schematic to be this:Note some connections not filled in due to being hidden; most of them going to the big connector LW1.Datasheets I found:RY1 - relay -https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/2601/JR%20Relays.pdfTR1 - BJT NPN -https://pdf-html.ic37.com/pdf_file_B/20200531/pdf_pdf/PdfOld/icpdf_datasheet_9/ET391_datasheet_93455/152354/ET391_datasheet.pdfUnfortunately I was unable to find the datasheet of PM Mitsubishi Electric QM10KD1-HBMeasurements:R-S: 17KohmR-T: 9MohmS-T: 9MohmU-V: 25KohmU-W: 187ohmV-W: 25KohmAny tips&tricks regarding how to diagnose this? I'm not very well versed in power electronics so I'm a bit out of my depth here.I'm hoping I can get this going again. Any help is appriciated~
Yet Another Keysight 3458a ERROR 202, “HARDWARE FAILURE – SLAVE TEST: DC BOARD” - Page 1
Forum section: electronics / repair

author: skjafar
author_rank: Contributor
timestamp: May 12, 2024, 11:57:41 am
content: Hi all,I had posted in Metrology but I have not received any help. I was hoping maybe @TiN can provide some help.Anyway I hope somebody here has some information.I have the following error when the device does the self-test:ERRSTR 202, “HARDWARE FAILURE – SLAVE TEST: DC BOARD”No other errors reported.No measurement is being made. Even TRIG didn't trigger a measurement.We sent the device for service at Keysight, they asked for "only" $7.5k to replace the DC Board and A/D board plus a calibration. I didn't foresee such a bill. So I didn't do the repair. It's such a valuable device to sit as a paper-weight though. Please help me get it running again.Here are the faults reported by Keysight:Time out unable to read A/D. Cal value Out of Range "95"Can anyone who knows this device explain what this means?I found U2 on the DC board damaged, they relays were not running, after replacing it they are working again but the failure didn't clear.Please note that this is a device I bought brand new around 2014 and it was never tampered with before this incident.After injecting 1V through the terminals, I see 1V on both TP10 and TP11 but Q12 is off and it is not passing this voltage to P4. Q12 is controlled by a signal coming from the 8051 uC which is indeed disabling it. Does the system do this because it failed the self test? maybe as a safety feature?Do you have suggestions?

author: coromonadalix
author_rank: Super Contributor
timestamp: May 12, 2024, 12:08:22 pm
content: double posting is not permitted

author: skjafar
author_rank: Contributor
timestamp: May 12, 2024, 07:53:51 pm
content: My bad, I was not able to remove the other post.I think it's more suitable to post it here in "repair".

author: Simon
author_rank: Unknown
timestamp: May 12, 2024, 08:05:18 pm
content: So give me a link to your other one and I will delete/move it for you.

author: skjafar
author_rank: Contributor
timestamp: May 14, 2024, 08:40:58 am
content: I've done some measurements around in the A/D board as well.HTRIG is low, but that's because the RAMP signal is also zero volts. Then I checked TP404 which is giving me 0.4V, then check both analog switches on C408 and C409 they are shorted and the capacitors are not discharging.Control pins TP401, TP402 TP403 are not changing, even when I do an AutoCal, screen shows sampling indicator blinking but HTRIG is not changing.
Yet another no-good TV, yet another set of SMPS secondary filter caps. - Page 1
Forum section: electronics / repair

author: technix
author_rank: Super Contributor
timestamp: October 09, 2022, 09:45:02 pm
content: Someone was trying to sell a TV for $25 but it was returned as no good. I took it home for free hoping to fix it.I took it apart, and went straight for the power board and inspected the secondary capacitors. 12V only, Capxon. Okay they are sus, and they gotta go.Out goes two 470uF/35V and a 220uF/25V and in goes two Jamicon 1000uF/25V and 470uF/25V caps. Looks fixed now.The problem is, why are those secondary output filter caps so darn unreliable? I have fixed so many TVs, monitors, set top boxes etc with that exact same fault. Even some enterprise networking gear suffers from bad caps. Grrr

author: wasedadoc
author_rank: Super Contributor
timestamp: October 09, 2022, 10:41:11 pm
content: I don't know which of these applies.1. The designers are incompetent.2. The designers do understand but do not adequately specify to manufacturing what capacitors to use.3. Component buyers ignore what has been specified, especially if they come across a cheaper component or if the original is difficult to obtain.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 09, 2022, 10:42:57 pm
content: Design life.The caps are fine, for what they are. Give or take occasional formulation mistakes, but that's happened even to large brands. This particular brand makes as wide a range of products as anyone else; all of which will do more-or-less what the datasheet says. If the type chosen isn't well suited to the application, or a longer lifetime is desired (a desire you are asserting, not the manufacturer!), you get unexpected failures.Key word, "unexpected". The manufacturer is happy with calculated lifetime, and their customers are happy enough at the price point. Assuming, you know, a fair market and stable equilibrium and all. Which... sometimes.Also assuming that it's past EOL. You didn't give a mfg date, which would probably give it away (if it's labeled at all, anyway).Tim
Yet another Tektronix 465 repair - Page 1
Forum section: electronics / repair

author: MarkKruetzmann
author_rank: Contributor
timestamp: November 07, 2019, 05:10:36 pm
content: Hi!I recently bought a dead 465 which now sits naked on my bench. I measured the low dc voltages and they are all down. Yippee! Finally something that is actually broken and needs a repair!Anyway, the service manual I have seems to have no circuit diagram of the power supply, only the detailed block diagram. Does anybody know a decent service manual available online? I'm asking because there seem to be some options and I don't want to dig through all of them just to find missing pieces or faults.Mark

author: jdragoset
author_rank: Frequent Contributor
timestamp: November 07, 2019, 06:15:24 pm
content: http://w140.com/tekwiki/wiki/465

author: andy3055
author_rank: Super Contributor
timestamp: November 07, 2019, 10:51:19 pm
content: https://archive.org/details/tektronix_465

author: med6753
author_rank: Super Contributor
timestamp: November 08, 2019, 07:27:11 am
content: Start with the +55V reference. If it's low all the supply voltages will be off.
Yidun Lighting JHL-L201 movement sensor switch - Page 1
Forum section: electronics / repair

author: perdrix
author_rank: Frequent Contributor
timestamp: April 19, 2023, 08:09:49 am
content: My bathroom cabinet has one of these motion sensor switches:https://yidunlighting.cn/led-hand-sweep-sensor-switch-p00174p1.htmlIt appears to have become intermittent. It is unfortunately completely potted with what I think is epoxy.I've tried contacting the manufacturer in China to see if with will supply one of these but I'm not hopeful.Has anyone ever repaired on successfully?ThanksDavid

author: Swake
author_rank: Frequent Contributor
timestamp: April 22, 2023, 06:28:55 pm
content: The sticker on the thing in the link you provide says it is IR. Likely there is a sender and a receiver IR LED in that detector.Search for "LED hand sensor module" on aliexpress. Plenty of those modules so it seams:-https://www.aliexpress.com/item/4001361328280.html-https://www.aliexpress.com/item/1005002323656937.html-https://www.aliexpress.com/item/1005005141616020.htmlI think you can just desolder the LED's on the module and replace with that round metal detector on yours.
Yihua 3005D-II, two resistors burned (magic smoke escaped) from one channel - Page 1
Forum section: electronics / repair

author: mancausoft
author_rank: Contributor
timestamp: December 01, 2023, 11:11:25 am
content: I'm trying to repair my Yihua 3005D-II, one problem is that the mosfet (?) near the damage is blank (no number at all)Did you know if the schematics are available, I search on google but nothing.Did you have some hint to debug the problem?
Yihua 3010d-iii bench power supply "SCP" error - Page 1
Forum section: electronics / repair

author: jetuaime81
author_rank: Newbie
timestamp: February 29, 2024, 04:05:34 pm
content: I bought a yihua 3010d- iii psu. The problem is I am not able to inject voltage and heat components; as soon as short is detected, SCP error comes up (short circuit protection). I tried in many voltage and current settings but shorting gives SCP. CC works properly when a load is connected but that is not why I purchased this. The seller isn't agreeing to replace or refund. The video below clearly shows it should not give SCP when shorted; pardon me it's in Indian language. Is there anyway to disable SCP on this board? Or maybe a work around? My requirement is to check shorts on motherboards so I will need to inject as low as 1V.https://youtu.be/uGIf2_m2sPw?feature=shared&start=265
Yihua 858d hot-air - intermittent temp-sense issue? - Page 1
Forum section: electronics / repair

author: julian1
author_rank: Frequent Contributor
timestamp: September 17, 2023, 04:18:31 am
content: My 858d hot-air station has performed flawlessly for years.But it just developed a fault where the display starts showing wrong values and temperature regulation is lost.So the display will show 129 or 730 instead reaching and showing the set voltage of 350C.And the fan won't stop, after the hand-piece is cradled, because it doesn't sense when the hand-piece has cooled down.When the cable is twisted/ turned, then the issue will often fix itself and it works for a bit.But then the cable is twisted/manipulated again through use, and it fails.Has anyone seen this particular issue before - and know if its a bad-connection issue somewhere -It is difficult to pin-point whether it's the hand-piece, cable, or station connector that's at fault.

author: kripton2035
author_rank: Super Contributor
timestamp: September 17, 2023, 07:31:05 am
content: Yes my yihua station almost burned into flames some years ago for no reason.was working fine , but decided it was time to change for a quick 861 ... don't regret it.
YIHUA 992DA+ REPAIR - NOT WORK - Page 1
Forum section: electronics / repair

author: Pchelpnuoro
author_rank: Newbie
timestamp: April 08, 2022, 02:33:34 pm
content: Salve a tutti ho un problema da ieri con la mia 992DA+. Improvvisamente non è più partita l'aria calda rimane impostata 200° oppure su qualsiasi temperatura, ho smontato la pistola perchè ho capito che il problema era proprio li infatti ho trovato il filo che funziona con la calamita danneggiato. Ho sistemato tutti i fili perchè erano molto usurati.Unico problema è che non riesco a capire il funzionamento del sensore calamita per far avviare la stazione. Allego le foto , se qualcuno può farmi capire come collegare le due parti altrimenti la stazione non si avvia e non scalda.Perdonate il mio inglese ma sono italiano.Hi everyone I have a problem since yesterday with my 992DA +. Suddenly the hot air no longer started, it remains set at 200 ° or at any temperature, I disassembled the gun because I realized that the problem was right there in fact I found the wire that works with the magnet damaged. I fixed all the wires because they were very worn.The only problem is that I cannot understand the functioning of the magnet sensor to start the station. I am attaching the photos, if anyone can make me understand how to connect the two parts otherwise the station will not start and does not heat up.Forgive my English but I'm Italian

author: Chris56000
author_rank: Frequent Contributor
timestamp: April 08, 2022, 06:49:33 pm
content: Hi!Your picture isn't too clear but your gun needs a replacement magnetic "dry reed switch" – it looks like the original has got broken for some reason!The magnets are made of a material that is only magnetic up to a certain temperature, so the gun will heat until a certain temperature is reached, at which time the magnets become "non–magnetic" and the switch opens, sending a "turn off" signal tothe controller unit!Therefore you need to get something like this:–https://www.ebay.co.uk/itm/Dry-Reed-Switch-RI-70-1-8x7mm-Magnetic-Switch-Normally-Open-Contact-Switch-/323781810533?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=710-127635-2958-0. . .soldered to the yellow and orange connections where the old broken switch was connected!Alternatively, you can get a compatible complete replacement desoldering gun here:–https://www.ebay.co.uk/itm/220v-Tool-Hot-Air-Desoldering-Gun-for-KADA-850-852D-Rework-Station-/313802950112?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=710-127635-2958-0. . .Ensure you order the correct voltage for your local supply – I think Italy will be 220/230 V!The tube between the gun and the control unit is designed to carry both the air from the control unit pump and the electrical leads to the control unit – the leads are threaded through the hot–air port and then connected to the appropriate. terminals in the control unit itself!Chris Williams
Yokogawa 7555 front current post/fuse holder needed - Page 1
Forum section: electronics / repair

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: September 07, 2023, 06:28:18 pm
content: Hi everyone, I'm looking for a source of the fuse holder/post for current measurements for the front of the 7555 Yokogawa meter.I believe it could be different model, I've checked 7562 and it fits as well.Maybe somebody has a broken meter and would be willing to sell the part or sell a whole meter...

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: September 07, 2023, 06:30:48 pm
content: I was thinking maybe somebody could 3d print it?

author: Stray Electron
author_rank: Super Contributor
timestamp: September 08, 2023, 03:05:58 am
content: I've seen something similar used on an HP meter. Possibly the HP 3468. I wonder if it's the same part used for both meters, or possibly made that meter for Yokogawa?

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: September 08, 2023, 05:20:40 am
content: Checked 3468, that’s not the one, but it may be some idea taking in consideration close cooperation between Yokogawa and HP.

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: June 14, 2024, 04:21:17 am
content: I've got 10 of those fuse holders straight from Yokogawa thanks to kindness of one of the contributors on this forum.Big thanks and of course I've got extras so I could share in case somebody needs one... or two.
Yokogawa DL1540CL scope needs calibration (corrected scope model number) - Page 1
Forum section: electronics / repair

author: sambuddy200471
author_rank: Newbie
timestamp: November 12, 2024, 07:29:51 am
content: Hello,I have twoDL1640CLDL1540CL Yokogawa scopes that operate BUT the battery has died in both of them. I have replaced the battery in one of them so-far...and it seems happy. BUT, it is in serious need of calibration. Does anyone know how to calibrate one of these?(I have contacted a couple of companies that calibrate Yokogawa scopes....but the ones that responded have said they dont do this ,model)CheersStuart

author: GGMM
author_rank: Frequent Contributor
timestamp: November 12, 2024, 10:26:17 am
content: Hello,I fixed one but not required to recalibrate.See this doc, in principle there is a possibility of self-calibration.Good luckcdt

author: sambuddy200471
author_rank: Newbie
timestamp: November 12, 2024, 10:40:19 pm
content: Thanks for the manual.I had a look and found that I had posted the incorrect Scope model number (have since corrected it). I did have a look and that menu option on my scope but that Cal function appears to be a "fine tuning" calibration function. My issue is all my Cal and setup data is missing completely, which means the input gain is way off.. e.g. the square wave Cal signal barely shows on the display when I have the input sensitivity set to 10mv/div.Cheers

author: aeg
author_rank: Regular Contributor
timestamp: November 12, 2024, 11:16:49 pm
content: Are you sure this is a cal problem and not a faulty front-end? Are all 4 channels like this? Does it pass self test?

author: sambuddy200471
author_rank: Newbie
timestamp: November 13, 2024, 12:56:24 am
content: well, thankyou for asking that @aeg . That question made me do some more investigation and this is what i found1: I ran all the tests and they passed, so i looked closer (like i should have done earlier)2: I was getting no square wave cal signal on the front panel because the front panel was dislodged abit. (now fixed)3: My voltage readings we still off. Someone had plugged in the incorrect probe for the scope (now fixed)My scope is now working as it used tooThanks
Yokogawa DL1740E LCD problem - Page 1
Forum section: electronics / repair

author: Ahax
author_rank: Newbie
timestamp: November 27, 2024, 04:31:15 pm
content: Hello, I recently acquired a Yokogawa DL1740E scope. The LCD is realy dim. Does it need to be replaced or could there be something else wrong with it. If it inded does need to be replaced does anybodyknow what kind of LCD I should buy?Thanks

author: TERRA Operative
author_rank: Super Contributor
timestamp: November 27, 2024, 10:41:23 pm
content: I would check the backlight first. It may be possible to replace just the CCFL tube with a new one. I've done the same in a few Tektronix TDS220 scopes.It may even be possible to replace the CCFL with LED's, there are a few of us that have done it on various scopes here on the forum (The Tektronix THS720 scopes for one example).
YOKOGAWA DL7200 - Page 1
Forum section: electronics / repair

author: yuebhugo
author_rank: Contributor
timestamp: September 04, 2021, 03:35:57 am
content: DL7200

author: yuebhugo
author_rank: Contributor
timestamp: September 04, 2021, 03:37:07 am
content: DL7200

author: yuebhugo
author_rank: Contributor
timestamp: September 04, 2021, 03:44:12 am
content: DL7200

author: yuebhugo
author_rank: Contributor
timestamp: September 04, 2021, 03:45:42 am
content: DL7200

author: yuebhugo
author_rank: Contributor
timestamp: September 04, 2021, 03:46:41 am
content: DL7200

author: yuebhugo
author_rank: Contributor
timestamp: September 04, 2021, 03:47:44 am
content: DL7200

author: yuebhugo
author_rank: Contributor
timestamp: September 04, 2021, 03:48:39 am
content: DL7200

author: yuebhugo
author_rank: Contributor
timestamp: September 04, 2021, 03:54:49 am
content: Anyone can share the schematic of YOKOGAWA DL7200?

author: pcwrangler
author_rank: Regular Contributor
timestamp: September 04, 2021, 05:20:15 am
content: Have you tried the service manual?https://xdevs.com/doc/Yokogawa/Yokogawa%20DL7100_7200%20Service%20Manual.pdf

author: shakalnokturn
author_rank: Super Contributor
timestamp: September 04, 2021, 08:45:32 am
content: Thanks for the photos.I quite like Yokogawa scopes, they don't show up often over here though.Funny that the ASIC's should be marked Yokogawa, I'd expect them to be made by NEC.The way the buzzer is mounted is a bit odd, what were they thinking?Quote from: pcwrangler on September 04, 2021, 05:20:15 amUnfortunately there are no component-level schematics. I'm not sure I've ever seen any for a Yokogawa DSO.
Yokogawa DLM2024 video problem - Page 1
Forum section: electronics / repair

author: rob10k10
author_rank: Newbie
timestamp: October 25, 2022, 04:15:00 pm
content: Hey guys!I'm working on Yokogawa's oscilloscope that I bought with video problem. When I tested it first time, the image was always abstract, sometimes changing the pattern. The image is the same on the onboard video and the VGA output.I checked the power supply and it looks good (no ripple). Looking at the board I found a FPGA that's responsible to generate both video outputs. I realize too that this FPGA warm up a little (around 60°C) so I asked to a friend to do a reballing process on the FPGA, guessing the heat generated some connection problem between the IC and PCB.The reballing process solved part of video issues. Now I can see the video normally during some minutes (or seconds) if the oscilloscope is cold (ambient temperature). After some time when its on due the heating the image gets abstract. If I turn off and turn on after some minutes, works fine again.Any guess to solve this problem? I attached some pictures of the main board and video problems. I didn't find service manual or schematic.Robinson.

author: rob10k10
author_rank: Newbie
timestamp: October 25, 2022, 06:27:22 pm
content: There are some other interesting details: some menus has weird backgrounds (images attached).

author: Gominalo
author_rank: Contributor
timestamp: October 25, 2022, 09:46:19 pm
content: Looks like corrupted RAM, check if it has a self ram test.

author: rob10k10
author_rank: Newbie
timestamp: October 26, 2022, 08:38:42 pm
content: There is only ROM test.

author: Gregory
author_rank: Regular Contributor
timestamp: October 26, 2022, 11:34:30 pm
content: I thought of bad ceramic capacitors or BGA soldering problem..But the broken menus indeed sound like a bad memory chip
Yokogawa TY720 multimeter parts - Page 1
Forum section: electronics / repair

author: C-47
author_rank: Regular Contributor
timestamp: March 19, 2023, 11:39:46 am
content: I have the TY720 for many years and the coloured plastic shrouds that go around the input jacks, break and no longer provide support especially when using straight banana plugs. I have checked with the agent in Oz, no spare parts even though the meter is still sold, only option to return to Japan for repair and $$$.I wonder if anyone knows where to obtain such items or if there was a 3D drawing to enable PLA or Resin printing, the wall thickness is quite thin at 0.8mm. Thanks, Alan.

author: C-47
author_rank: Regular Contributor
timestamp: March 22, 2023, 11:24:41 am
content: Update:Obtained some Acetal rod and machined up shroud, had to be in 2 pieces to keep the lathe setup fairly simple as wall thickness was just on 1mm, used Loctite 401 as adhesive along with Loctite 770 as a pre agent, seems to be holding so far, but it was a reasonably good push fit anyway. Unfortunately Acetal doesn't come in Red, so some Texta colour on the white stuff will have to do. Now I have the basic dimensions will try and Resin print some once I learn CAD drawing.
Yokogawa TY720 multimeter, screen low contast - Page 1
Forum section: electronics / repair

author: jpaudio
author_rank: Newbie
timestamp: June 12, 2023, 09:25:38 am
content: Hello,I recently purchased a Yokogawa TY720 RMS multimeter. This is a high end multimeter from a well known company. Unfortunately, the LCD screen has a low contrast and its reading from an angle different than front of it is blurry. I sent it back to local distributor, but he reported back that there is no any electronic issue, all units of this range have this difficulty and factory cannot do anything more about. I opened the unit but there is no any pot (like old days...) to adjust its contrast. Also they have not Service Manual to send me (!)Has anyone of you this manual to see if contrast can be adjusted from secret-service menu (if any)?Thanks in advance for your kind attention.Regards,John
Yongnuo YN600EX-RT Repair - Page 1
Forum section: electronics / repair

author: Miti
author_rank: Super Contributor
timestamp: August 24, 2019, 10:41:47 pm
content: I have a Yongnuo YN600EX-RT that I bought few years ago for my Canon T5i. As I am just a weekend photographer, or rather holidays photographer, it was very rarely used. In the last few weeks I tried to use it for some events and, even though it apparently worked, I observed that the zoom was staying on M (manual) no matter what settings I tried. I remember that when I bought it, it used to follow and display the zoom of the lens. After I banged my head to the wall trying to find the setting that I was missing, I realised it was defective. Another symptom actually made me think that. The stepper motor that drives the zoom mechanism was hitting the end of travel not detecting the limit switch, every time I would power it on.Looking for some videos on YouTube, mainly to see how to open it, I found the following video. I was tempted to follow this procedure.But then I was out of peanut butter and I tried a different approach.Some guys found a cable that goes from the head to the electronics below, unplugged from the bottom connector. Too late, I opened the head anyway. Nothing seemed to be wrong there, the limit switch seemed to work well, and so does the switch that detects when the reflector is inserted.I've opened the bottom side, the brain of the flash and I tried to re-seat the connector that is linked to overheat error. Then I gave it a try and on top of my initial defect, the overheat error showed up so I was sure the problem is around that connector.Sure it was, crack line opens on four of the pins and the mechanical pin.I re-soldered that connector and it is alive again, as good as new.I've attached some pictures, they may help someone.I was too anxious to see if it works and I forgot to take pictures when I opened it and put it back together, but it is not big deal. Few screws and you're in.
YST-SW800 Yamaha Subwoofer SMPS repair help - Page 1
Forum section: electronics / repair

author: Hman545
author_rank: Newbie
timestamp: September 08, 2021, 03:09:14 am
content: Hi guys, I have a subwoofer that I'm trying to repair, it has a faulty SMPS and need help finding suitable alternative power transistors.I've got the repair manual and found 4x blown power transistors and 2x resistors blown open.They are:2x 2sc4140 (TO3P)2x 2sc4163 (TO-220F)Can't find those transistors new anywhere, so I've found alternatives.https://au.element14.com/on-semiconductor/fja13009tu/transistor-bipol-npn-400v-to-3p/dp/2450767andhttps://au.element14.com/on-semiconductor/fjpf13007h2tu/trans-npn-400v-8a-150deg-c-40w/dp/3368627I only understand the bare minimum how transistors work and what all the specs mean as I'm still learning.Are the above replacements suitable or should I use something else?(Also before anyone asks, I'm aware of the dangers of working on mains voltage equipment and am taking relevant precautions.)

author: David_AVD
author_rank: Super Contributor
timestamp: September 08, 2021, 03:17:28 am
content: Check the price on a replacement board (from Yamaha Aust) as sometimes they are surprisingly cheap and make repair not worthwhile.

author: Hman545
author_rank: Newbie
timestamp: September 08, 2021, 03:49:52 am
content: Quote from: David_AVD on September 08, 2021, 03:17:28 amHmm, I'm fixing this sub for fun and as a learning experience so I'd rather try repair it.
zd-987 zd987 desoldering station - Strange behaviour - Page 1
Forum section: electronics / repair

author: Mamejay
author_rank: Contributor
timestamp: October 06, 2023, 11:04:07 pm
content: Hi guys,I have a zd-987 desoldering station which I have had for a few years.What I found today which I never really noticed was that when the auto temp shutdown kicks in, the pump has heaps more power. You can hear it in the motor speed.What I want to do is have that amount of power all the time while the gun is heating and at temp.Any ideas where I should be looking?

author: Chris56000
author_rank: Frequent Contributor
timestamp: October 07, 2023, 02:00:37 pm
content: Hi!This is due to deficiencies in the internal power supply circuit, what's happening is that when the heater shuts down in the "sleep mode", the voltage to the pump motor rises quite a bit!There's not a lot you to can do to improve the internal power supply without a major PCB re–design, but if you fit a panel–mounting external 2.5 mm DC power connector to the back panel, you can wire an external power supply (e.g., an old laptop charger) to the pump motor via the microswitch in the handle/gun assembly!It might be worth opening the unit and looking for any bulging/dried–up electrolytic capacitors on the main board as well!Chris Williams
ZD8915 De-soldering Station - Temperature Sensor Help - Page 1
Forum section: electronics / repair

author: brim2full
author_rank: Newbie
timestamp: November 06, 2021, 11:01:40 am
content: I'm in the process of reverse engineering my new ZD8915 de-soldering station.Why? because I can but also because it has an issue with incorrect temperature. When set to 220 degC it indicates 220 but actually measures 260 degC.What I'm specifically interested in is the resistance of the temperature sensor (I'm assuming the sensor is some form of PTC resistor and not a thermocouple). But if any one knows otherwise then please feel let me know.I would appreciate several persons who have one of these machines, or similar (and the inclination) could measure the resistance between pins 1 and 2 of the connector together with the nozzle temperature. A few machines should suffice. My machine is shown below.Model: Resistance (Ohms): Nozzle Temperature (degC):ZD8915 47 21Many thanksGreg
ZD915 Desolderingstation - No suction in gun - Page 1
Forum section: electronics / repair

author: Filurkatten
author_rank: Newbie
timestamp: July 08, 2019, 07:58:25 am
content: Hi.I bought a a zd915 desolderingstation a couple of months back and it have been working great up until a few weeks ago when the gun suddenly stopped suck up the solder.I can hear the pump from inside the unit loud and clear like it allways have sounded like and the gun still melts the solder.Do anyone have any experience with this problem and possible suggestions?Thanks in advance!

author: Muttley Snickers
author_rank: Unknown
timestamp: July 08, 2019, 08:22:31 am
content: From what you have described it could be a broken rubber diaphragm on the pump as mentioned in the thread linked below, you will need to open the unit up and have a look around inside for any obvious failures.https://www.eevblog.com/forum/repair/thinking-of-buying-a-zd985-desoldering-station-vacuum-pump-diaphragm-fail/

author: Filurkatten
author_rank: Newbie
timestamp: July 08, 2019, 08:41:05 am
content: Thanks for the quick reply.Will open it up later this week an check the pump.Allways good to have a starting point where to look.

author: Muttley Snickers
author_rank: Unknown
timestamp: July 08, 2019, 09:00:42 am
content: Quote from: Filurkatten on July 08, 2019, 08:41:05 amStart with the gun first and check that it's not simply blocked up with slag, blockages are common and frequently occur on these units. You could also disconnect the vacuum hose from the front of the unit and check for any suction before taking the unit apart, also check that the vacuum hose is intact and hasn't come adrift from somewhere.

author: Terry01
author_rank: Frequent Contributor
timestamp: July 08, 2019, 09:02:38 am
content: Maybe the nozzle is blocked. Have you tried running the cleaning rods through it when the tip is hot?

author: Filurkatten
author_rank: Newbie
timestamp: July 08, 2019, 09:27:31 am
content: I have cleaned the nozzle but will do it again just to be sure, will check the hose connection this eving.Again, thanks for all the quick replysIts much appriciated.

author: Filurkatten
author_rank: Newbie
timestamp: July 09, 2019, 04:31:25 am
content: I found the problem.At the connection point of the gun hose an unit there are a rubber washer, it had a small crack and didnt seal properly.I found a replacement at the local hardware store and now it works.Thanks for taking your time and pointed me in the right direction.
ZD981 soldering iron plug wiring pinout - Page 1
Forum section: electronics / repair

author: UserError
author_rank: Newbie
timestamp: May 06, 2023, 08:10:19 pm
content: Further to my ZD987 post, I've gone inside the case to try and trace the wires and the PCB states ZD981 (which is presumably the the soldering station only?). Anyway, if anyone has the wiring for this, I'd be very appreciative as I can't work out what does what - there's a triple connector to the PCB but I've no idea what it does as it's not labelled.
ZD985 flashes on randomly - Page 1
Forum section: electronics / repair

author: rilliam
author_rank: Newbie
timestamp: December 14, 2017, 12:05:58 pm
content: I have a ZD985 Desoldering Station that randomly turns itself on momentarily.Power cable plugged into AC.Front rocker switch set to OFF position.How can I fix this? Is my house going to explode?

author: Ranayna
author_rank: Super Contributor
timestamp: December 14, 2017, 12:17:46 pm
content: Wow, this reminds me that i wanted to open a thread about that as well.I'm not at home right now, so i'm not sure if my desoldering station is the same model, but it seems i have the same phenomenon happening.Plugged in, switched off, every few minutes i see a very short flash from the display, and i hear a sound coming from the station.I'm in germany,so i do not have polarized plugs, could that be an issue? I have not yet tried to reverse the plug.It works fine when i use it.

author: rilliam
author_rank: Newbie
timestamp: December 14, 2017, 12:24:48 pm
content: haha yeah I kept putting it off as well!Here is an image of mine:

author: Ranayna
author_rank: Super Contributor
timestamp: December 14, 2017, 12:39:07 pm
content: Ok, mine is different.The handle looks the same, but different color. I'm sure i saw a video with the same one as mine on either EEVBlog or BigClive.I think it's ZD-915, but i'm not fully sure.

author: vdtoorn
author_rank: Contributor
timestamp: September 17, 2024, 11:21:04 pm
content: Hi, sorry for trying to resurrect this very old thread, but I have exactly the same issue, did you ever find a solution?

author: beatman
author_rank: Regular Contributor
timestamp: September 18, 2024, 07:35:52 am
content: I have solder peak sp1010r desolder station and is doing the same thing every few seconds or minute.Possible solutions is to reverse the power plug or power the unit from other wall outlet or instal 4 pole power switch on the unit or external power adaptor with 4 pole on of switch.

author: Ranayna
author_rank: Super Contributor
timestamp: September 18, 2024, 11:07:27 am
content: I reversed the plug of my desoldering station, that eliminated the flashing display issue.I only use it very rarely and i have not encountered any other problems.
ZD987 iron plug wiring pinout - Page 1
Forum section: electronics / repair

author: UserError
author_rank: Newbie
timestamp: May 03, 2023, 08:58:02 pm
content: Hello, I have a ZD987 soldering station which has resented being moved around - a number of the wires have snapped off the pins on the iron's plug and I can't work out which wire goes to which pin. The plug has 6 pins and I've only been able to find 5 pin diagrams. Would anyone have the pinout for this, many thanks.
Desoldering station ZD_915 vacuum pump - Page 1
Forum section: electronics / repair

author: hubsy
author_rank: Newbie
timestamp: April 01, 2021, 10:27:24 am
content: Hi Guys,I've had a ZD_915 desoldering station for many years.The vacuum pump is running but no vacuum.On inspection, one of the bellows has split.I've searched but can't find replacement bellows.Any pointers please...

author: Muttley Snickers
author_rank: Unknown
timestamp: April 01, 2021, 11:40:24 am
content: I recently had a few repairs to do on my ZD-917 after it lost suction altogether. Long story short one of the internal hoses had split and also the little spacers between each of the diaphragm rods had flattened out causing the rods to bind. I machined up a couple of new spacers out of brass and now the machine really sucks.Anyway, another member named EJP had the same problem as you and they managed to get a few spare diaphragms from Zhongdi, perhaps you could send the member a message and ask if they have any spare diaphragms left, the thread is linked below.https://www.eevblog.com/forum/repair/thinking-of-buying-a-zd985-desoldering-station-vacuum-pump-diaphragm-fail/

author: hubsy
author_rank: Newbie
timestamp: April 01, 2021, 01:51:09 pm
content: Thank you Muttley Snickers, Have sent him a PM.

author: OZ1LQB
author_rank: Regular Contributor
timestamp: April 01, 2021, 02:36:07 pm
content: Hubsyi found mine herehttps://www.ebay.co.uk/itm/MEMBRANA-IN-GOMMA-RICAMBIO-ZD915-ZD917-SSD-15-SSD-17-37-ZD915R1/331526957130?hash=item4d308be84a:g:hAoAAOSwlG5ciM7Q
Zebra (Elastomeric) Connector Alternative For Brita Filter Timer LCD - Page 1
Forum section: electronics / repair

author: Trurl
author_rank: Regular Contributor
timestamp: September 29, 2022, 04:32:18 pm
content: My Brita filter jug's LCD Timer finally went blank recently, so I purchased a few new CR1616 lithium batteries. But even with a new battery the LCD display did not light up. So I reluctantly took out the PCB, and realized that it had been connected to the small LCD via a small strip of Zebra (elastomeric) connector.I tested each of the lithium battery by itself as well as on the PCB and the voltages were around 2.8~2.9 volts so the batteries are not the issue. The PCB seems to be good as well - the LCD displayed partially for a short while then tended to fade. Even with the Zebra strip, and the PCB/LCD leads cleaned with alcohol, the LCD only lit up sporadically even with pressure on the Zebra strip. Now, the LCD does not light up even with pressure on the Zebra strip.I think the Zebra strip is finally dead. Is there an alternative (method) to Zebra (elastomeric) connector for connecting a PCB and LCD?
Zener 3T 4148 voltage rate - Page 1
Forum section: electronics / repair

author: sdancer75
author_rank: Frequent Contributor
timestamp: February 28, 2021, 06:56:48 pm
content: I couldn't find anything....I need to replace a burned zener. It is marked 3T 4148 if I read well.How much is the reverse rating voltage?Thanks

author: madires
author_rank: Super Contributor
timestamp: February 28, 2021, 07:06:00 pm
content: Maybe a standard 1N4148, and not a Zener?

author: sdancer75
author_rank: Frequent Contributor
timestamp: February 28, 2021, 07:42:48 pm
content: It seems like a zener. Orange glass is classic package for zeners but how can I be sure? Its from smps and it's on the primary side just before the optocoupler

author: madires
author_rank: Super Contributor
timestamp: February 28, 2021, 07:50:41 pm
content: Then reverse-engineer that part of the circuit to figure out what the diode is meant for.

author: sdancer75
author_rank: Frequent Contributor
timestamp: March 01, 2021, 06:07:34 pm
content: Looking again the part under my microscope, I can say it says ST4148 and not 3T4148 I mentioned originally. I google it and I found that it's a switching diode despite the fact that many alibaba and aliexpress webpages describe it as zener.So, I suppose I can safely replace the part with the 1N4148. Do you agree?

author: madires
author_rank: Super Contributor
timestamp: March 01, 2021, 06:21:55 pm
content: Yep!

author: wraper
author_rank: Unknown
timestamp: March 01, 2021, 06:26:07 pm
content: Quote from: sdancer75 on February 28, 2021, 07:42:48 pmIt's not solely for zeners. If it has 4148 written on it, it's 1N4148. Zeners have different marking.

author: fzabkar
author_rank: Super Contributor
timestamp: March 01, 2021, 06:34:49 pm
content: See the references to ST4148 in the following circuit diagrams:https://www.abcelectronique.com/forum/attachment.php?attachmentid=66088
Zener diode in PS1 PSU (Solved) - Page 1
Forum section: electronics / repair

author: ShmoeMo
author_rank: Newbie
timestamp: October 12, 2019, 10:43:53 am
content: Hey guys, Fixing a friends PS1 as it had a ringing power supply and was smoking a little. I have found that one of the zeners on the output was shorted i have removed it and powered it up and the psu now works but i need to replace the zener. Does anyone know what the voltage of the zener is? Its listed a d103 / MAZ9120D0LS0-TX/L on the schematic and on page 21 of this manual. Every time i google the "part" number i just get linked back to psu manuals.manualowl.com/m/PlayStation/SCPH-7501/Manual/330626?page=21#manual

author: RES
author_rank: Regular Contributor
timestamp: October 12, 2019, 11:34:22 am
content: Found this info here:http://datasheetz.com/data/Over%20Voltage,%20Current,%20Temperature%20Devices/TVS%20-%20Zener%20Diodes/MAZ9120H0LCT-datasheetz.htmlPart Number: MAZ9120H0LManufacturer: Panasonic - SSGSeries: -Short Description: DIODE ZENER 12V 200MW MINI-3P?

author: ShmoeMo
author_rank: Newbie
timestamp: October 12, 2019, 02:35:50 pm
content: Ahhhh thank you so much. Yeah i couldnt find nothing on datasheets, no matter how pages i went through.Makes sense that it would be a 12v zener. Should have some laying around.
Zener Diode part ID please help - Page 1
Forum section: electronics / repair

author: knudsenuk
author_rank: Contributor
timestamp: May 12, 2024, 11:36:03 am
content: Hi EveryoneI have a failed zener diode with 22A 51 written on it. Would anyone know how I can find a replacement?many thanksRichard

author: fmashockie
author_rank: Frequent Contributor
timestamp: May 12, 2024, 03:25:45 pm
content: This is actually very likely a TVS diodehttps://www.mouser.com/datasheet/2/240/media-3320418.pdfI see this a lot on newer boards where ZD refers to a TVS diode.

author: knudsenuk
author_rank: Contributor
timestamp: May 13, 2024, 07:04:25 am
content: Thanks for your help. That would make more sense than it being a Zener.
Zener Planar Diode ZPD - Page 1
Forum section: electronics / repair

author: gmc
author_rank: Regular Contributor
timestamp: November 21, 2022, 10:24:07 pm
content: I have a faulty ZPD 4V3 diode. According to the data sheet it's a zener planar diode which is a term I've not heard of before (planar)Data sheet here:https://www.tme.eu/en/details/zpd4.3-dio/tht-zener-diodes/diotec-semiconductor/zpd4-3/What's the difference between this a normal zener diode. Can I use a BZX55C4V3 for example it's place?https://www.vishay.com/docs/85604/bzx55.pdf

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 21, 2022, 10:28:22 pm
content: All diodes are planar; it might've been a term of note in the early years, perhaps it's a very old product line?Looks completely identical to the BZX series yes.Tim

author: gmc
author_rank: Regular Contributor
timestamp: November 21, 2022, 10:42:02 pm
content: Thanks. Learnt something new.It's a diode from the early 80's so that would explain the terminology.

author: DavidKo
author_rank: Frequent Contributor
timestamp: November 23, 2022, 11:44:22 am
content: The name was used to distinguish them from point contact diodes. Today 99% of diodes are the one produced by planar technology.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 23, 2022, 04:45:05 pm
content: I would expect it's a lot higher than that... but once you get into the question of "how many nines?", clearly there's a lot, regardless.Tim

author: gamalot
author_rank: Super Contributor
timestamp: November 23, 2022, 05:09:09 pm
content: When I was a kid, the most common one in China was point-contact germanium diode 2AP9.