hybridfree/eevblog-posts huggingface dataset:
Metex ms2000 repair - Page 1
Forum section: electronics / repair

author: lameralik
author_rank: Newbie
timestamp: October 11, 2019, 01:42:06 pm
content: Hello! I have the metex ms2000 device, at inclusion continuous peep and the dark screen. If there is a scheme, will be grateful. Thanks! If who knows the brand of the processor write please.

author: Emo
author_rank: Regular Contributor
timestamp: October 11, 2019, 02:00:06 pm
content: Hi,Conrad still has documentation on this Metex scope meterSucces!Eric

author: lameralik
author_rank: Newbie
timestamp: October 11, 2019, 02:06:36 pm
content: Thank! But it seems to me that this is not a scheme from him, but from a slightly different model. And the processor name is not quite visible.
Metrahit 18S - Page 1
Forum section: electronics / repair

author: najrao
author_rank: Regular Contributor
timestamp: August 22, 2023, 01:01:08 pm
content: Picked up this 'Rishabh' 18S in clean condition, for a low price.Though unmolested, it does not work for 'diode', capacity and ohms. For diode, I get a continuous beep and zero reading even with probes unplugged. The ohms fails to auto zero with probes shorted, and displays a wandering hundreds to megohms.Two diodes, apparently back to back, are SHORTED. See them just under the daughter board on the left.Yes, I have read through the multiple threads on Gossen Metrawatt in our forum.The manufacturer has not done a good job of soldering, and has not cleaned the board at all after, it seems. I want to do this too.Request help to locate the fault and save this excellent instrument. Thanks.I have read through the multiple posts in this forum.Edit: The two diodes are NOT shorted. There is a R50 across them.I did remove them to check, unnecessarily.

author: shakalnokturn
author_rank: Super Contributor
timestamp: August 25, 2023, 12:23:10 am
content: It looks as if someone has had a try at fixing it before, there has been solder rework on the resistors around the switch.If it looks dirty take it apart and scrub it all clean, when repairing handheld DMM's delaying this step has often proven to be a waste of time.Also consider that the switch may have been previously disassembled and not realigned correctly.Have you been able to confirm with a known good meter that V and A are giving correct readings?If you do disassemble for cleaning make the most of it to take better photos, you'll have more chance of getting help.

author: najrao
author_rank: Regular Contributor
timestamp: August 25, 2023, 04:43:48 am
content: Thanks, Shakalnokturn.I have solved it ! : Small compression spring hiddeninsidethe red switch contact carrier was simplyabsent! It is essential, to hold the contact pressed lightly against the switch tracks. It's absence was inferred by beeper test.Snapping open the contact carrier was awkward to say the least. I managed to find a spring to fit, and bingo!Unfortunately my new spring is bit harder to compress, which lifts the carrier arm an extra 0.5mm, and presses a little harder on the tracks. Finding an exact spring is a wild chase, and I would rather not try disassembing the all-plastic carrier again.The back of the board has a large plastic shroud which also carries the display and backlight. To gain access to the back of the switch, this shroud has to come off, but won't, without desoldering at least four awkwardly located pins at the back of the lcd.This makes cleaning impossible. Dunking the whole board in IPA is a way, but what about the pots and trimmers?I checked DCV calibration against an U1242 calibrated by Keysight. Very good! All other functions seem to work as intended.I need a user manual, Rishabh's support is useless. No download available anywhere.Thank you again for help.Edit: I got the exact spring from another Rishabh mule, perfect. R support sent me a scanned user manual, nice.
Metrahit 27M - Page 1
Forum section: electronics / repair

author: ober
author_rank: Contributor
timestamp: April 28, 2021, 04:37:57 pm
content: I have a Metrahit 27M that has one component (literally) vaporized, including a PCB trace leading to it. Since the fuse was missing at the time I got it, I think I can imagine what happened. Now I would like to put back the missing component, in order to see how much of the rest of the multimeter still operates. But I can't find any hi-res photos of the PCB (or, heaven forbid, schematics). The component is close to what might be MOVs or PTCs, visible even without the inner cover removed.Did existing owners of 27M (or 27I) multimeters take such PCB photos?

author: ober
author_rank: Contributor
timestamp: April 28, 2021, 04:44:24 pm
content: Oh, here is a photo:

author: Manul
author_rank: Super Contributor
timestamp: April 28, 2021, 08:31:15 pm
content: It is probably something in parallel or in series with the input. If it is in parallel, just leave it like this. If in series, put a jumper. It is probably the best shot to quickly test the input and see if the meter is alive. If you get positive result, then it is worth to dig some more, and think what this part might be...

author: ober
author_rank: Contributor
timestamp: April 29, 2021, 03:21:13 pm
content: In DCV mode, the display is fluctuating between a couple V and a couple hundred V. Putting in a voltage or shorting the leads doesn't change things, but coupling in a bit stray AC to one or two of the leads does (up to a beeping overload indication).So it seems the gap is in series. Just right to it is a 0-ohms resistor (probably also as a fusible), so another one of those might be the most likely assumption.

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 29, 2021, 06:26:56 pm
content: You're probably right.Before going straight for a 0 Ohm you could try fitting 10k ohms as a current limiting test, it may give you 10k added offset on Ohmmeter and should have little noticeable effect on Voltmeter.
Metrahit ETECH long time to settle - Page 1
Forum section: electronics / repair

author: giosif
author_rank: Frequent Contributor
timestamp: March 12, 2022, 07:52:40 pm
content: Hi all,I am checking a Metrahit ETECH multimeter and one annoying thing with it is it takes a long time for the readings to settle (at least in DCV).If I apply, say 9V DC, the readings jump to something like 8.957V, and then slowly creep up to something like 8.990V (this is just an example, not actual readings).Overall, this might take something like 20 seconds or so to settle.I am trying to understand if this is the symptom of a problem with the meter, or whether it might be "normal" behaviour.Anyone out there with the same meter who could confirm, please?Thanks!

author: giosif
author_rank: Frequent Contributor
timestamp: March 12, 2022, 10:29:45 pm
content: Just to add more context, I traced the circuit from the V input of the meter up to the "ADC" IC.By the way, quick insight, this "ADC" IC is usually lasered off in these series of Metrahit DMMs.However, this one was left intact and I could determine what IC it is: it's a Fortune Semiconductor FS9704B.This looks to be a full blown multimeter IC but, in this case, Gossen seem to have decided to add a TI MSP430F149 as the brains of the multimeter, which then talks to the FS9704B via bus transceiver ICs.Coming back to the topic of this thread, as I was saying, I traced the circuit from the V input up to the FS9704B IC (going to pin 18) and it all checks out.I also traced the circuit from COM to the same IC on pin 25 and there are not issues there either.So, there is no issue with the input analog circuitry, as far as I can determine.

author: giosif
author_rank: Frequent Contributor
timestamp: March 13, 2022, 05:47:22 pm
content: An update on this: after letting the board soak in IPA and cleaning it with a toothbrush, it looks like the problem has gone away and the meter readings settle much quicker now.And I learned a little bit more about these meters, in the process.
Metrahit m26 - Page 1
Forum section: electronics / repair

author: PE1IDY
author_rank: Newbie
timestamp: July 30, 2025, 08:33:40 pm
content: I bought a metrahit m26 with a problem.The strange thing is that the 2 parts from the inputTo the pcb are not populated.I mean not the movDoes someone know what these are and what is the value ?

author: giosif
author_rank: Frequent Contributor
timestamp: July 31, 2025, 01:17:55 pm
content: Both are resistors:- The smaller one is a 100 kOhm Allen Bradley resistor;- The larger one is, I believe, a 620 Ohm fusible resistor.And the black component next to the two resistors is a PTC (typically, around 1.1 kOhm), if that's what you meant with "MOV".If you meant the blue component further to the left, that is indeed a MOV.

author: PE1IDY
author_rank: Newbie
timestamp: July 31, 2025, 04:53:01 pm
content: Aha , that is nice.Thanks for your replyNow i can go on with the repair

author: giosif
author_rank: Frequent Contributor
timestamp: August 01, 2025, 07:18:32 am
content: Good luck, and let us know how the repair goes!
Metrawatt Metrawin 14s not working - Page 1
Forum section: electronics / repair

author: duzycinek
author_rank: Contributor
timestamp: November 17, 2022, 08:49:21 am
content: Hello, anyone faced issue like this? All digits and symbols on LCD are activated at start, but nothing else happens. Any ideas? Looking forward to hearing from you!

author: shakalnokturn
author_rank: Super Contributor
timestamp: November 17, 2022, 10:46:04 pm
content: G-M-C meters like most DMM's will enable all LCD segments on power-up as part of the self/user test.I'd start with the usual checks:On board power supply voltages.Function selector switch contacts to MCU in case it is receiving invalid function information.MCU oscillator.MCU reset.I²C bus integrity.

author: duzycinek
author_rank: Contributor
timestamp: November 18, 2022, 06:02:54 am
content: Thank you, I will check.

author: duzycinek
author_rank: Contributor
timestamp: December 11, 2022, 10:35:53 am
content: Hello, the problem were buttons. Multiple were pressed at once. Without buttons is working perfectly. From side I can see that they are very close to press point. Should I make it shorter and put new conductive rubbers? Looking forward to hearing from you!

author: duzycinek
author_rank: Contributor
timestamp: January 02, 2023, 11:52:12 am
content: After shortening rubber poles and replacing conductive rubbers multimeter is working again!
Metrawatt Metriso 1000V Isolation Tester - Page 1
Forum section: electronics / repair

author: david77
author_rank: Frequent Contributor
timestamp: July 23, 2020, 09:48:16 pm
content: Hello eevbloggers.I recently bought this isolation tester as ex-army surplus. It's quite an old unit, probably made in the 1970ies but it is complete and looks like new.The HV part works fine and it also measures AC voltage, but it should be possible to use it as high current resistance tester, too. There is a switch position labeled "D", which I assume to mean "Durchgang" - german for "Continuity". However the instrument does nothing in this position.I haven't got either user manual or service manuals. So it could easily be a case of PEBKAC as well.Maybe somebody here has used one of these before or maybe somebody has a scan of a manual for it.I'll upload a picture of the unit later.Thank you!Davidedit: spelling

author: coromonadalix
author_rank: Super Contributor
timestamp: July 24, 2020, 02:16:19 am
content: with the correct model on the gossen website you can find the user manuals

author: david77
author_rank: Frequent Contributor
timestamp: July 24, 2020, 11:57:23 pm
content: Quote from: coromonadalix on July 24, 2020, 02:16:19 amSadly not for this device. I looked.
Metrix AX 323 - Page 1
Forum section: electronics / repair

author: gianluigi
author_rank: Contributor
timestamp: June 04, 2021, 05:19:34 am
content: Hi,I have power supply Metrix AX 323 with2 output 0-30V 2.5A and one 4.5-5.5 5AHas anyone schematic or service manual?Thank you

author: shakalnokturn
author_rank: Super Contributor
timestamp: June 04, 2021, 06:55:00 am
content: Attached schematic for the older version of the AX322with switches rather than potentiometers for the current limiting, I expect it to have a lot in common with the AX323.Hope it helps...

author: gianluigi
author_rank: Contributor
timestamp: June 04, 2021, 07:28:47 am
content: Thank you,another diferrence is that AX 323 has LM324n on each section of output

author: Jack133
author_rank: Newbie
timestamp: March 30, 2025, 02:12:16 pm
content: Hello gianluigi;I repair my AX323 with LM324 too and I drew the schematic of the seconde channel, you can find it on my github:https://github.com/stephdaniel133/Metrix_AX323/tree/mainThe schematic is available directly under LTSpice to simulate it.I hope it helps you
Metrix GX240 - Page 1
Forum section: electronics / repair

author: Kidon
author_rank: Regular Contributor
timestamp: May 27, 2020, 01:26:54 pm
content: Hi, I have a Metrix GX 240 Signal Generetor that I picked up recently.I just plugged it in this morning, and found out the although all the Signal Forms and other features arefunctional, the output voltage, which should be 20VDC at maximum, is only a few millivolts.Both of the 50R output terminals are connected on the board via a SDM resistor (impossible to read what’s on it; probably mounted upside down), and it’s actually a dead short.Does anyone have a schematic for this? I can’t find it anywhere...Thanks...

author: shakalnokturn
author_rank: Super Contributor
timestamp: May 27, 2020, 04:23:21 pm
content: Most of those around in France have previously been used in highschools. If you have a dead output the odds are that a pupil will have sent some powerinthe output, most of the time destroying the output transistors at minimum.

author: sorenkir
author_rank: Regular Contributor
timestamp: May 28, 2020, 07:39:59 pm
content: Hi,In my GX245 (which is the 5MHz version of the GX240), the output amplifier is a LT1206.Do you have a similar output amplifier ?Michel.

author: odium
author_rank: Contributor
timestamp: May 31, 2020, 09:56:03 pm
content: hi,you can find some schematics of the ITT branded version in this french document attached (students work about understanding how the device works).schematics found in pages 4 and 6 ..hope it helps a bit …cheers !

author: Uchristo
author_rank: Newbie
timestamp: January 27, 2021, 10:19:33 am
content: Can somebody tell me which transformer is used in there? Mine seems to be defect. I desoldered the bridgerectifiers and the fuse still blews immediately.The device was working the last time A year ago or so. I noticed the fuse being not 50mA like printed on the back but 160mA. I tried wirh up to 500mA but the fuse always immediatwly blews.I measured the resistance on primary(230V) side, it‘s 72Ohms. Secondary sides are 1,3 Ohms (for 5V DC rail) and 8,3 Ohns (for -15V/+15V rail)

author: Kidon
author_rank: Regular Contributor
timestamp: February 01, 2021, 05:54:09 pm
content: Quote from: Uchristo on January 27, 2021, 10:19:33 amI sent you a private message

author: Kidon
author_rank: Regular Contributor
timestamp: February 01, 2021, 05:56:58 pm
content: Whaooo,I didn’t receive any notifications, but now I see that many people responded.A little late, but thank you all.
Metrix MTX3250 strange behaviour reading Ohm - Page 1
Forum section: electronics / repair

author: munnik
author_rank: Newbie
timestamp: February 21, 2024, 09:37:08 am
content: Hi,I've just acquired a Metrix MTX3250 multimeter, and I'm very happy with it. There is only one strange issue that I can not understand or resolve. Hopefully you can help me with this.When I put the multimeter in Ohms mode and the test leads are disconnected, the multimeter shows000.00 Ω. I would have expected to show.OL MΩ. When I connect the test leads from the MTX3250 to another multimeter and put that other multimeter in VDC mode, the MTX still reads000.00 Ω. The other multimeters shows5.6077 VDC. When I change the MTX from auto range to manual range, I can find the expected value of10.926 MΩ. The other multimeter then shows a value of0.6142 VDC. When I step down one range, the MTX3250 shows.OL MΩand the other multimeter shows1.1034 VDC. All other ranges show000.00 kΩ,00.000 kΩ,0.0000 kΩand000.00 Ω. For all these ranges, the other multimeter reads between5.1113VDCand5.608VDC. When I have the correct reading in manual mode and switch back to auto ranging, the reading remains correct. Continuity seems to be working fine on the MTX3250.Is this maybe a software issue? The current version of the software is 1.05.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 21, 2024, 01:32:28 pm
content: Unless you have some antenna effect with probes, or high impedance who charge up the input stage ....You should ask Chauvin Arnoux .....could be FW issues ... check if there are updates

author: shakalnokturn
author_rank: Super Contributor
timestamp: February 21, 2024, 11:56:04 pm
content: That's a bit of an unusual problem.Are capacitor and current measurements working as expected ?I would tend to think that it's software or at least bus related.I don't think the schematic for this model is around but if I'm not mistaken the ASIC is the "DMM5" (new version).There are schematics for a handheld model using DMM5 posted by Vince in this topic:https://www.eevblog.com/forum/testgear/metrix-mx56c-bk-precision-5390-multimeter-teardownThat should give you a general feel of how things work. Note that the DMM5 (ITT) used in this schematic although functionally almost identical isn't the same as the DMM5 (Metrix) used in the MX24B and I suppose in your MTX3250.They made minor changes to the silicon between the two, I've tried swapping them in the past: Everything works but all the measurements are wrong by a set factor so likely some modification was made to ADC reference voltage. In case you come to the conclusion the autorange in the DMM5 is whacked look for nothing older than the MX24B for a parts donor.First try to figure out how the CPU and DMM5 are communicating during range switching see if it looks FW related, could be worth checking on calibration EEPROM accessibility too.
Metrix MX51EX showing offset voltage on startup - Page 1
Forum section: electronics / repair

author: JIROB
author_rank: Newbie
timestamp: August 13, 2020, 08:58:18 pm
content: I've purchased a Metrix MX51EX but it's showing a DC voltage of about -2.8v and OL on mV range.Running a fuse check for F1 (500mA Littlefuse) it appears to fail OL indicating a blown fuse.My instinct is that the offset on voltage on startup without any connections isn't going to be fixed by a new fuse and this may show an underlying issue that's more than a cal to fix.Does anyone have any experience of these meters or any insight into what might be up with this thing?If it's not an easy fix it'll be a return job....Thanks for the help,Jim

author: shakalnokturn
author_rank: Super Contributor
timestamp: August 14, 2020, 01:21:25 pm
content: Usually battery contamination.Start by checking under the black foam on the PCB..How does it behave on Ohms?Once you're fixed on the pollution, it's worth disassembling the rotary switch for a check or preventive regluing of the contact springs.

author: JIROB
author_rank: Newbie
timestamp: August 14, 2020, 09:01:30 pm
content: Ah, thats good info, thanks. Not sure how to open this up to check inside though.The battery compartment looks clean with no leakage signs. New battery makes no difference.The Ohms is showing something similar @4Mohms, slowly dropping.Clean on all other settings which is what had be baffled.I've left it on for most of the day and it's slowly drifted down to -0.627V across that period but still shows OL on mV. Doesn't return to -3.7V previous reading even with switch off and on again.Readings match my other dmm (Fluke and Metrix) when I test voltage. Does this make sense?

author: shakalnokturn
author_rank: Super Contributor
timestamp: August 14, 2020, 10:13:04 pm
content: Yes, to me it further confirms the PCB is contaminated.The readings won't be off in most cases, I'd expect some error for high value resistance measurements.Opening the case isn't hard once you know, easy to butcher when you don't.The clip-locks at the ends need pushing inwards while slightly levering the 2 halves of the case appart.It's hard to know how much leverage to apply, the water-proofing washer does offer some resistance adding doubt to whether you've actually released the locking clips.

author: JIROB
author_rank: Newbie
timestamp: August 15, 2020, 10:27:45 pm
content: Thanks so much for your help on this. Not had time to get into the thing yet but stumbled across someone doing a teardown of a B&K Precision 5390 which is a Metrix in disguise and has the same case etc..https://www.eevblog.com/forum/testgear/metrix-mx56c-bk-precision-5390-multimeter-teardown/
METRIX OX7042 - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: January 21, 2025, 02:51:35 pm
content: Hello everyone! I am looking for the characteristics of 3 4-legged smd quartz, because we can no longer see the inscriptions on them....The device is a METRIX OX7042 SCOPIXII portable oscilloscope....Thanks to anyone who could take pictures of the card...I am attaching the pictures...Thanks for your help

author: coromonadalix
author_rank: Super Contributor
timestamp: January 21, 2025, 03:43:53 pm
content: search for the nearby mcu's to give you an idea of the frequencies used for themthoses xtal generally have an : vcc, ground, enable pin, and Hz outputit seems you have some kind of coating on the pcb use some acetone on them to remove it, the markings are generally engraved on them, no worries to erase markingsgood luck
Mettler PM PJ Linearity board - Page 1
Forum section: electronics / repair

author: gmac34
author_rank: Regular Contributor
timestamp: January 21, 2025, 09:43:14 am
content: I'm making a dedicated post to collect the info I have on a modification to the PM and PJ series of Mettler scales. This small board adds a linearity potentiometer replicating the circuit that the previous generation of Mettler scales had (PE series).The PM series does linearisation in software, the linearisation parameter are stored on a EEPROM but cannot be programmed without a service cartridge. IES Corporation developed this small board back in the 80s when this cartridge was apparently difficult to come by, even tough it became redundant for them over the years it is now again quite difficult to get hold of the original service kit from Mettler, at least for a hobbyist like me. Therefore the board becomes again a valid solution to correct linearity on old scales.The board is mentioned in their great Handbook as the PML Linearity Board please refer to It for the installation instructionshttps://www.iescorp.com/HB.htmThe short version is that you should repalce IC13 (a mettler branded LM358 ) with the board, and connect a jumper wire from the board to the left side of the reference resistors.The board includes two opamp, one is the LM358 that can be reused, the other can be an LM741, LT1097, 1001 etc.The resistors are all 1% but should have relatively low tempoco, I used 25 ppm/K 1/4W ones.I have made a layout based on IES description, Attached you can find the Kikad prject files as well as fabrication files.
Mettler Toledo AB204 balance PSU (3 pin) - Page 1
Forum section: electronics / repair

author: Ashhhhh
author_rank: Contributor
timestamp: January 08, 2020, 08:09:18 am
content: Hey all,I've obtained this balance, minus the PSU/Adaptor.Does anyone know the voltage and pinout of this 3 pin connector?I've emailed Mettler and they're not really interested or perhaps unable to answer this question.Cheers,Ash

author: Lorenzo_1
author_rank: Regular Contributor
timestamp: January 08, 2020, 11:06:45 am
content: This document appears to give the PS specs:https://www.marshallscientific.com/v//vspfiles/specs/MTABPBSB_specs.pdfHope this helps

author: Ashhhhh
author_rank: Contributor
timestamp: January 08, 2020, 11:16:56 am
content: Thanks!Any idea on why the plug is 3 pin?

author: Ashhhhh
author_rank: Contributor
timestamp: January 13, 2020, 05:43:01 am
content: Nobody?

author: TheMG
author_rank: Frequent Contributor
timestamp: January 14, 2020, 12:59:24 am
content: Probably an earth ground pin.
MGE UPS Pulsar ESV 22+ connection mystery, help - Page 1
Forum section: electronics / repair

author: kkamel
author_rank: Contributor
timestamp: June 10, 2024, 09:36:24 am
content: HiI got 3 of the mentioned UPSs they require external battery box to work, I managed to find the manual but no information about the batteries connection whatsoever, is it 24V or 48V? What makes it even harder is that there are 2 mysterious white pins beside the black and red going out to the battery box, I don’t know if they are mid point batteries measurement, temperature sensor connection or what?I think MGE systems are gone long time ago and I can’t refer to any technical support.I am planning to have 2 of them as backup as I have frequent outages, and the third I will scavenge it’s components.I attached some photos, if someone one have experience with this type of UPS or similar I would appreciate your help.Thanks,

author: kkamel
author_rank: Contributor
timestamp: June 10, 2024, 03:35:40 pm
content: Just an update I measured the transformer output it’s 26V, so I think the batteries should be connected as 24V, but I still don’t know the function of the extra 2 white wires going to the battery box?
MGE UPS - Pulsar M 3000RT Repair assistance - Page 1
Forum section: electronics / repair

author: stephenvr
author_rank: Newbie
timestamp: November 17, 2023, 11:46:50 am
content: Good day all! Newbie here and my first post. I have 6 of the above mentioned ups that need repairing. No circuit diagram, so firstly, I'm asking if anyone has schematics. Error on most of them is 707 - min invert voltage ..I picked on a post that one should check capacitor C14 for low capacitance. This was the case in all with them measuring 10% of the value. I also noted that capacitor C9 had also lost most of its value. These capacitors form part of the input filtering by the looks of it. Once these were changed, the units came back with same error, or error 007 (fan) or other errors.Can anyone assist me with further with a schematic or guidance?

author: kripton2035
author_rank: Super Contributor
timestamp: November 17, 2023, 01:53:48 pm
content: there are not a lot of inverter schematics out there, and less even for commercial ones...did you check the batteries ? most of the times this is the only problem, and they all fail with bad batteries one day or another.

author: stephenvr
author_rank: Newbie
timestamp: November 17, 2023, 01:58:16 pm
content: Hi kripton2035, new batteries.I know C14 plays a role in this fault as once changes, you get different errors. Sometimes if you leave the unit on and just keep trying to restart, it might actually start and then run with no problems at all. Thanks for responding though.
Mi Curved Gaming Monitor 34" - Horizontal lines - Page 1
Forum section: electronics / repair

author: Kikerumbo
author_rank: Newbie
timestamp: March 14, 2024, 08:46:31 pm
content: Hello everyone,Thanks in advance for any help you can provide.I have a Mi Curved Gaming Monitor 34". A few weeks ago it started to show (or not showing) horizontal lines. Of course, it's outside of the warranty period.After some hours of reading and watching videos I disassembled the monitor and checked the ribbons that go from the TCON board to the panel PCB. If I disconnect the ribbon for the right side of the panel, the other half shows a perfect image. I ordered a "new" TCON, installed it and the issue persists so that tells me it must be a panel issue.I've seen various videos talking about "the tape method", covering the clock signals (I believe). I don't understand much of electronics but I can't believe that's a solution (it has to have some kind of performance loss, maybe in the refresh speed?). If those connections weren't needed, they wouldn't be there. I don't think manufacturers do anything they don't need to.Anyway, I can't find the right pads in the ribbon cable to block.Now the question. Is it an issue with the panel itself or with the PCB of the panel? I suppose that if it is a panel issue I better throw it in the trash, but if it is a PCB issue it can be repaired. If the latter is true, can you help me find the issue?Monitor model: XMMNTWQ34.Panel model is: Samsung LSM340YP05.TCON: CCPD-TC-340-001.Panel PCB: CCPD-XR-340-001.Thanks again!

author: RayRay
author_rank: Frequent Contributor
timestamp: March 15, 2024, 05:45:16 pm
content: Have you tried swapping the ribbon cables to verify it's not a faulty one?If you lightly press down on the COF (chip on film) transparent/yellow cable on right side of the panel board (while the monitor is working) does it make any difference?
Michrochip Brand Unknown Smd Component - Page 1
Forum section: electronics / repair

author: 2X
author_rank: Frequent Contributor
timestamp: February 26, 2024, 09:06:11 pm
content: Hello,I have an smd component with the marking "CS0938" from Microchip company and I can't find any datasheet of it. You know if I have to remove some letters from the marking code in order to search for the datasheet? This PCB is from a trackball from a scan machine.

author: DavidAlfa
author_rank: Super Contributor
timestamp: February 26, 2024, 09:12:14 pm
content: 99% it's a voltage regulator given the large capacitors connected to it.Probably a 5V->3.3V LDO.

author: fzabkar
author_rank: Super Contributor
timestamp: February 26, 2024, 09:20:26 pm
content: I expect that "GAD" is the marking code."0938" appears to be the YYWW date code. In fact there is a similar date code on the EEPROM (949)."CS" appears to be the part ID. It's the 3.3V version of MCP1700.MCP1700T-3302E/MB, Microchip, Low Quiescent Current LDO, 3.3V, 250mA, marking CS, SOT89:https://ww1.microchip.com/downloads/en/DeviceDoc/MCP1700-Low-Quiescent-Current-LDO-20001826E.pdf

author: 2X
author_rank: Frequent Contributor
timestamp: February 26, 2024, 09:54:17 pm
content: Quote from: fzabkar on February 26, 2024, 09:20:26 pmhttps://gr.mouser.com/ProductDetail/Microchip-Technology/MCP1700T-3302E-MB?qs=WWgnj3qycfnlJJhwyn%2Fifw%3D%3D
Micro Hard Radio Repair - Page 1
Forum section: electronics / repair

author: Sully
author_rank: Newbie
timestamp: January 25, 2020, 09:16:59 am
content: Hello all!I am attempting to salvage this radio board. The board's antenna coax was dragged across the positive terminal of a 12v battery during installation in a pelican case. The technician describe a pop sound, then promptly ordered a new board. I'd like to fix it - this is my first attempt at SMD work. This is a pic of the damaged area. The trace does not appear to be burned, so I'd like to R2 the parts but don't their values. Research I've done (Google and YouTube) indicate it may be a common .1uF capacitor but wanted to run it by the famed EEEVblog group for analysis. The second image is a pic I pulled from Micro Hard's site (http://www.microhardcorp.com/pX2-dev-kit.php).Regards,Sully

author: SMdude
author_rank: Frequent Contributor
timestamp: January 25, 2020, 10:02:09 am
content: I would say that it is a ferrite bead for the power input to the device. This is there for EMC compliance purposes, you could most likely replace it with a 0 ohm resistor(or bridge it) and the unit will work assuming nothing else was damaged.Measure the resistance of the part next to it to confirm. It will most likely look like a dead short, it is probably 0.1 ohms or something like that. Those 2 parts are the same. If it doesn't read really low resistance, then disregard the advice above!You should also be able to trace that those parts connect to the pins in the power plug.
Micro potentiometer identification help - Page 1
Forum section: electronics / repair

author: gkmaia
author_rank: Frequent Contributor
timestamp: April 29, 2019, 08:18:51 pm
content: I am struggling to find a replacement for this one. Have anyone ever come across one of these?Shaft is +/- 3.5mm diameter.The one on the photo I am measuring has a broken shaft. Vr1 on top is an example with shaft.

author: LateLesley
author_rank: Frequent Contributor
timestamp: April 30, 2019, 01:06:42 am
content: The closest I can find is these, if it's any help??https://www.aliexpress.com/item/10PCS-Great-IT-Rv09-Vertical-12-5mm-Shaft-1k-2k-5k-10k-20k-50k-100k-0932/32995902380.html?spm=2114.search0104.8.12.73627fbbAdTcyz&transAbTest=ae803_5https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20190429170432&SearchText=potentiometer+20K+vertical+1cm
Micronta 22-191 MOV - Page 1
Forum section: electronics / repair

author: mzacharias
author_rank: Frequent Contributor
timestamp: August 02, 2019, 09:33:12 pm
content: Won't replace any of my Flukes, but I picked up a broken 22-191 multimeter for 10.00 total.Bad MOV, can you guys suggest a rating for a replacement?Marked 7K820, Google isn't turning up much.Here the bad MOV and it's position in circuit.

author: wraper
author_rank: Unknown
timestamp: August 02, 2019, 09:42:41 pm
content: 7mm diameter 82V DC varistor. There are tons of suitable replacements.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 02, 2019, 10:18:10 pm
content: I got one of those for free, but the lcd was faded to the strip not being held on anymore. I tried to fix it, but ended up shipping it to an user (Harvey) in England? (can't remember now) who loved these meters and wanted more.More athttp://kuzyatech.com/micronta-22-191-multimeter-teardown

author: mzacharias
author_rank: Frequent Contributor
timestamp: August 03, 2019, 12:25:22 pm
content: Quote from: retiredcaps on August 02, 2019, 10:18:10 pmI've owned like three of these over the years, including this one now. They're really quite handy. Once the AC and especially DC internal adjustments have been corrected for aging, general service including cleaning switches etc, they're OK.The performance doesn't match up to the newer Chinese models, but the physical build quality is really nice in some respects. Strong cylindrical input jacks, really strong physical construction of the switches, that sort of thing.This one works fine after temporarily removing the MOV. It's a really clean one.As I said, it won't replace any of my Flukes, but it takes me back to my early days as a tech.
Micronta 22-210 Ohm & Continuity Circuit(s) problem - Page 1
Forum section: electronics / repair

author: 22-210
author_rank: Newbie
timestamp: January 05, 2024, 06:26:34 pm
content: Hello,I'm new here and repair is pending receipt of an EEVb BM235 to replace my 22-210. I've got some pictures of the 22-210 PCB backside and rotary switch and another "piece" that seems to go nowhere. Wondering if someone might confirm this other "piece" does or does not contribute to the fix? I've not removed the PCB for component testing just yet. Also wonder if there should be TWO sets of three-finger contacts on this rotary switch rather than just the one set shown? It has holes drilled for mounting a second contact set, it would seem. At one time I did have a 1.5v battery decay/leak/corrosion issue which would be why that "piece" is corroded green, but that issue has been many years ago. And the finger contact screws have some green around them but all else looks clean.Thanks!

author: wasedadoc
author_rank: Super Contributor
timestamp: January 05, 2024, 08:38:29 pm
content: Schematic is in the manual available athttps://bama.edebris.com/manuals/micronta/22-210/One of the pictures athttps://www.radiomuseum.org/r/radioshack_micronta_analog_multimeter_22_210.html#shows ends of only two screws in the plastic of the moving contacts holder, strongly suggesting no second set of wipers.The long metal strip with central V appears to be part of S2 or S4. Whichever one it is not is the switch in your first photo. S4 supplies power to the transistor circuit producing the beep in continuity mode.

author: Runco990
author_rank: Frequent Contributor
timestamp: January 05, 2024, 09:56:10 pm
content: There is ONE set of 3 finger contacts. The strip with the V is probably the "indent" mechanism for the rotary switch and likely belongs on the other side of the board, someplace on the meter case.

author: 22-210
author_rank: Newbie
timestamp: January 06, 2024, 12:31:25 am
content: Well, yes indeed, that url has a photo like my first pic. I missed that last night when I looked at that accompanying wiring schematic and so did not realize those photos existed there - thanks so much! Indeed, it does look like that "piece" must fit somewhere on the other side of the pcb, as suggested. Weird, but I'd think the Ohm range(s) and Continuity would use a second set of finger contacts, especially since the omitted/absent contact set would be on the Ohmic side of the board (per the required front-side ClockWise dial rotation of the switch). I got a "parts only" 22-210 with busted meter scale glass on the way so will tear it apart and see what it reveals.Thanks
Microsoft Surface Book 2 Base (keyboard) / IC Identification  - Page 1
Forum section: electronics / repair

author: Kamynsky
author_rank: Newbie
timestamp: July 30, 2022, 07:22:04 pm
content: Hi EEVerybodyThis is my first post on this forum , but I've been lurking for a while and thank to you i've fixed some stuff already ,But this time I'm unable to find any information on the device I'm trying to fix .Patient :Microsoft Surface Book 2 base with GTX 1050What is happening :After connecting base to the tablet nothing works on the base , cannot undock , keyboard is not working USB's are not workingWhat I have checked :Took it apartNo water damageBattery is chargingMost of the board is not getting powerI have found one IC that is getting pretty hot like 60C + maybe more (I don't own thermal camera)Here is screen of the IChttps://prnt.sc/PmQUnBg8USZIDesignation on it seems to be 914C6H , but I'm unable to find itFrom what it is around it ,it looks like DC Regulator with Voltage sense ? (I'm noob )I would be grateful for any help
Microswitch Identification Help - Page 1
Forum section: electronics / repair

author: Helmanfrow
author_rank: Contributor
timestamp: January 19, 2020, 09:12:29 pm
content: Can anybody help me identify the red-capped switches for this Logitech M510 mouse?They're 6mm square by 4mm high.Part number or purchase link would be great!

author: Haenk
author_rank: Super Contributor
timestamp: January 20, 2020, 06:24:15 am
content: First, you need to measure them down to sub-millimeter precision - there are so many different sizes, and +/- 0,3mm will probably change the usability of the mouse.Then search eBay for "6mm omron" or "6mm microswitch" - and chose the right one.There are plenty of chinese alternative parts, for a mouse I'd go with quality parts though.

author: MarkF
author_rank: Super Contributor
timestamp: January 20, 2020, 07:57:38 am
content: They look like B3F switches from Omron.There are various sizes and heights.https://www.mouser.com/Electromechanical/Switches/Tactile-Switches/_/N-5g2mZ1yzvvqx?P=1z0x1bpZ1yzvpobZ1z0z63xZ1z0z2tt&Keyword=b3f+switches&Ns=Pricing%7c0&FS=True

author: Ian.M
author_rank: Super Contributor
timestamp: January 20, 2020, 09:03:19 am
content: Yeah. Those are 'Tactile Switches' not microswitches. The difference is the mechanism and form factor. There are a limited range of tactile switch footprints and any brand in the same footprint and with the same button height should be interchangable. Unfortunately one common failure mode is for the rubber dome under the button that provides the click (and the conductive rubber contact) to crack, distort or otherwise collapse, making it very difficult to measure the original button height.

author: Helmanfrow
author_rank: Contributor
timestamp: January 21, 2020, 09:03:02 pm
content: I didn't measure the pin pitch but according to the depth gauge on my Chinese calipers they are 6mm square and just over 4.3 mm tall.

author: Helmanfrow
author_rank: Contributor
timestamp: January 21, 2020, 09:09:55 pm
content: They DO look like B3F switches! B3F-1006 switches, to be exact!I bought a small bag of Omron switches some 15 years ago to repair what I thought would be a lifetime supply of my then favorite wired mouse, the IntelliMouse Optical 1.1A. Somehow all the mice have vanished since then but I still have the switches. Go figure.As it turns out this was a very popular switch model and came in handy repairing other mouse models over the years.

author: Helmanfrow
author_rank: Contributor
timestamp: January 21, 2020, 09:11:11 pm
content: Tactile switches! Yes! That brings up a whole 'nother set of search results. Thanks for the vocab tip!

author: fzabkar
author_rank: Super Contributor
timestamp: January 21, 2020, 09:12:31 pm
content: Quote from: Helmanfrow on January 21, 2020, 09:09:55 pmDo you have a cat?
Microwave oven - What kind of DC/DC Converter am I looking at? - Page 1
Forum section: electronics / repair

author: JannB
author_rank: Newbie
timestamp: December 16, 2024, 01:13:12 pm
content: Dear community,roughly one year ago I tore down an old microwave oven.Sadly I did not make any pictures of the whole oven (e. g. the type plate).The part of interest is a DC/DC converter populated on one of the PCBs I salvaged for later use.The information I have are the following:Typ / Art.-Nr.: ETXMJ197X1BGInput: ~ 325 VdcOutput: DC 12 V and DC 30 VWhat I want to know#1: Manufacturer#2: Dataseheet (Rated power, line regulation, load regulation, etc.)#3: Price / ValueI attached serveral pictures as well as the service manual for a similar microwave oven.The part of interest is referred with IC10.Unfortunatele the schematics are not searchable so you have to manually scroll to page 28 / chapter 19 to find the converter at the top middle.I tried to find this part at serveral venders without success.On mouser.com I get mostly open frame ones like:RECOM PowerRACM30-12DK/277/OF

author: fzabkar
author_rank: Super Contributor
timestamp: December 16, 2024, 03:30:13 pm
content: Manufacturer is Matsushita / Panasonic.https://www.partmaster.co.uk/images/mediator/121/av359wb.pdf(page 28)https://fcgresources.blob.core.windows.net/fcgpdfs/ED/00230.pdf(page 28)https://www.sm.azhand.co/ServiceManuals/KA/Microwave/NN-C784M(PTE).pdf(page 33)https://www.sm.azhand.co/ServiceManuals/KA/Microwave/NN-C784MF%28TTE%29.pdf(page 31)https://www.commentreparer.com/doc/34435/panasonic-nn-l750wb-nn-l760wb-pdf.pdf(page 92)

author: Ranayna
author_rank: Super Contributor
timestamp: December 16, 2024, 03:30:26 pm
content: I can at least help with the Manufacturer Logo:https://logowik.com/matsushita-logo-vector-36730.htmlThat distinct M stand for Matsushita.Googling Matsushita ETXMJ197X1BG returns a couple of service manuals like this one, listing the component:https://www.manualslib.com/manual/2800853/Matsushita-Electric-Nn-V688w.html#manualSo it's a custom part made internally, there will very likely be no public specs available.
Microwave oven with no rectifier - Page 1
Forum section: electronics / repair

author: jmelson
author_rank: Super Contributor
timestamp: November 18, 2024, 01:05:11 am
content: My wife's beloved 1984 microwave oven died a couple weeks ago. Fuse was blown, after some digging the HV capacitor had a shorted section. It was a 0.41/0.44uF dual-section cap rated at 2600 V. There was a cook/defrost switch that connected both sections in parallel for cook mode. The thing that has me stumped is I can't find a HV rectifier anywhere in the circuit. Yes, I can see that the magnetron could act as a rectifier, so you could build an oven that runs without a rectifier. But, one issue with doing that is that the transformer secondary would have DC in it that could saturate the transformer. The CLASSIC microwave oven circuit has the transformer feeding a capacitor that then has a rectifier with the cathode grounded and the cap/anode junction connected to the magnetron cathode. This circuit approximately balances the current in the transformer. The circuit in the existing oven seems to apply the raw secondary to the capacitor AND the magnetron cathode in parallel, causing the capacitor to have a lot of 60 Hz AC current flowing in it.Has anyone seen a microwave oven with this circuit?Thanks for any hints,Jon

author: CaptDon
author_rank: Super Contributor
timestamp: November 18, 2024, 02:22:20 am
content: Having only a half wave rectifier does not cause a D.C. imbalance in the transformer. In a typical microwave oven the rectifier and the diode action of the magnetron form a voltage doubler circuit. The capacitor charges on one half of the cycle and the the capacitor voltage is in series with the transformer secondary voltage of the other half of the cycle. I have never personally seen a microwave without the diode. Some ovens use an inverter and the diode is a bit hidden within the core of the inverter.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 18, 2024, 02:28:54 am
content: Quote from: jmelson on November 18, 2024, 01:05:11 amSuch designs were common in the 1970s/early '80s.

author: wilfred
author_rank: Super Contributor
timestamp: November 18, 2024, 04:13:38 am
content: Which fuse? Mine which broke some months ago wouldn't heat food but everything else worked normally. Mine had a mains input fuse and a high voltage fuse for the magnetron which had blown. The cause was one of the door switches had failed and was visibly charred. There were two other safety switches but this one did the heavy lifting. The HV fuse was hidden inside a 10cm long enclosure that completely covered the fuse holder. I can't remember if the switch failed open or closed.But mine was only twelve years old and is probably a generic design like every other off brand oven from China. Thankfully spare parts are in plentiful supply every other week on the roadside.
Micsig SATO1004 Wi-Fi not working - Page 1
Forum section: electronics / repair

author: GNasty
author_rank: Newbie
timestamp: May 27, 2024, 06:01:16 pm
content: How is everyone today? I am new to the forum, and hopefully I posted this in the right section. I am hoping you can point me in the right direction. I have a Micsig SATO1004 scope. I turned it on today and noticed it failed to connect to Wi-Fi. It shows all available networks in my area, but “failed to connect” pops up on the screen. I tried using my phone as a hotspot, and I still can not connect. I thought maybe this was a firmware update issue. I was able to connect directly through Ethernet to check for an update, but no updates were available. Do you have any ideas on how to get Wi-Fi working again?Thank you for the help.Kyle

author: m k
author_rank: Super Contributor
timestamp: May 31, 2024, 12:11:54 pm
content: First you must figure out somehow that scope's wi-fi is actually sending.So you need a device that can show you wi-fi frequencies.