hybridfree/eevblog-posts huggingface dataset:
APC SRT1000XLI bin from working UPS? - Page 1
Forum section: electronics / repair

author: strict
author_rank: Newbie
timestamp: October 08, 2024, 06:07:51 pm
content: Hello, electronic friends.I have APC SRT1000XL after short inverter part. IGBT was changed, driveer was checked. It's Ok now. UPS latched on error P.13/event107. Please, can anybody help me with bin EEPROM ic3 24LC64 from working UPS SRT1000XL? Thanks.
APC SU3000INET won't charge battery - Page 1
Forum section: electronics / repair

author: Sedu
author_rank: Newbie
timestamp: January 15, 2024, 06:55:19 pm
content: Hello everyoneI just bought APC Ups3000inet which is not charging batteries. Ups was delivered without batteries so I just bought 4x12v 17aH connected them in series 2x24v and..... Nothing.So I begin to check resistors and caps which are mentioned in this thread.https://www.eevblog.com/forum/repair/apc-smart-ups-su3000rm-overloaded-when-started-from-batteries/Of course R38 and R43 was fried but still managed to be 0.500k ohm so I have replaced them for 1k which is in schematic and all caps besides AC ones 1500uf/75v X3.When Ups have connected batteries and I plug it into AC it falls in some kind of bootloop I can hear relays clicking and nothing happens I have to click shutdown and then power at front panel and then Ups is turning on reporting 1 bar of battery charge and is not charging of course when it's plugged into AC and working I can power on a heater through UPS and it's working fine. Just not on batteries. When I disconnect AC Ups dies immediately.I have connected UPS to hyperterminal and I have managed to change battery replace date and check battery charge voltage and ups is reporting 27.07v and reports battery voltage 0.000Shouldn't be battery charge voltage 55v for 2x24v ?I I'm sure person before me wasn't doing anything in hyperterminal or in eeprom.After spending two days I did factory reset through hyperterminal. Of course nothing besides battery charge voltage didn't change. Now it's 12.9vI have checked every single solder path to be sure I didn't destroy anything when replacing caps but everything is still the same before and after replacing caps and resistors.Battery connectors checkedWhen I hold TEST button it reports 3 bars on battery charge after button release 1 bar and blinkingBattery voltage 26.50v x2Voltage from batteries is going fine to MB and read 52vAny suggestion would be very helpful

author: Vovk_Z
author_rank: Super Contributor
timestamp: January 16, 2024, 10:20:00 pm
content: Possibly, it has 2s2p batteries connection (like 1000-1500 VA models)? That's why it expects 27 VDC? (IDK).

author: Sedu
author_rank: Newbie
timestamp: January 17, 2024, 03:34:53 pm
content: I'm sure it should be 2x24v (48v). I have to connect DC power supply in place of batteries just to be safe and then change voltage charge to 55v. I will report results 😁

author: Sedu
author_rank: Newbie
timestamp: January 30, 2024, 05:32:50 pm
content: Problem solved, battery charge voltage has to be 55.1v in eeprom. Now everything works fine.
APC SURT1000XLI Failure (FIXED) - Page 1
Forum section: electronics / repair

author: Lorenzo_1
author_rank: Regular Contributor
timestamp: March 13, 2021, 12:59:35 pm
content: APC SURT1000XLI failed gradually over several days. It would run normally then the red FAULT LED would light up and it would switch line voltage straight through to the output. On restart it would sometimes start normally. Other times it would respond to Power On button with a single beep but no start-up; attempt to start only after the O button was pressed following Power On; or start with a different/unusual sequence of lights (which I didn’t capture). Most commonly it turned on the FAULT LED rather than BATTERY FAIL. When it finally failed terminally, start-up sequence was to boot normally (i.e showing expected pattern of lights) and coming online for a few seconds then failing with BATTERY FAIL on.Disconnected battery and tested voltage – 52V as expected with 4x12V in series. Checked and tightened all connectors. No change. Wasn’t until I tested battery pack on load tester that it turned out its output was dropping to 0V with no load. Pinned it down to one battery that read 13.5V when isolated but simply dropped out under the slightest load. Replaced it with an old, functional battery and all working fine. Posted in case others encounter similar strange behaviour on startup that could have a simple solution.
APC UPS CS650. seeking help. - Page 1
Forum section: electronics / repair

author: flaotte
author_rank: Contributor
timestamp: May 03, 2024, 12:49:22 pm
content: APC UPS CS650. It was in working condition. I decided to add a connector to external battery.During the process I connected battery wrong way. It stayed wrong polarity for 10-20sec, until I smelled something strange. The smell was going from the battery, not UPS board. No fuses blown.On the board there is no visible damage. When I power it from mains it does not power up, does not charge battery.On the other hand if it ispowered from the battery, it works just fine.Connecting the battery wrong way or dis-reassembling process destroyed mains power circuit. It is not charging, also it has no idea there is power on mains and will not trigger bypass relay.Does anyone has circuit diagram for this unit?any ideas/tips how to proceed?I am not very comfortable with high voltage, it would be nice to have a plan before I start poking random traces and points.p.s. Active fan is(was) in my todo list too... Also it is 400w unit, my planned load is 30-50w, should not overhead with extra batteries.

author: m k
author_rank: Super Contributor
timestamp: May 07, 2024, 10:45:27 am
content: Charge is its own thing, but can have a protection something.Measure with multimeter and start drawing.Inverter parts have a heatsink, the separated and smaller one can be a charger.Faulty charger circuit can pull the bypass switch power down.
APC XS 1000 with bad MOSFETs - Is high RDS(on) bad enough to replace? - Page 1
Forum section: electronics / repair

author: dmulligan
author_rank: Regular Contributor
timestamp: January 31, 2021, 07:48:44 pm
content: I am repairing an old APC XS 1000 which went bad on me a few years ago. First the batteries were dead, no problem I replaced those then I got the dreaded clicking noise. I let it sit for years and now I am finally repairing it.I replaced all of the 22uf capacitors, testing them with my mega328 transistor tester showed they were all quite bad. The click of death went away but now the overload led lights and the buzzer whines. I checked the supply voltages and output of the op amps and they look good so I moved on to the MOSFETs on the DC-AC inverter section. When testing I found Q3 and Q4 are shorted. Q5 and Q6 read 0.5 ohms for their rdson. The datasheet states <0.18ohms and 0.15 typical. Q1 and Q2 read 0.1 and 0.2 ohms.The mainboard I have is a 640-0253c and the only schematic I could find was for the 640-0253e. The vast majority of the components match except the MOSFETs in the AC-DC inverter section. The schematic just shows "0.18 OHM 200V PWR" for all 6 MOSFETs. On my board Q1-Q4 are PNP20NQ20T and Q5-Q6 are STP19NB20T. Obviously I should replace Q1 and Q2 and DigiKey has them in stock.My question is about Q5 and Q6. Should I replace them based on the high RDSon reading? If so what should I replace them with? DigiKey nor Mouser stock the P19NB20. It looks to be very similar to the PNP20NQ20T other than the latter has a lower RDSon, which should be better right?Thanks.David

author: tooki
author_rank: Super Contributor
timestamp: February 01, 2021, 12:10:19 am
content: I'm pretty sure those Q5 and Q6 are just fine.The measured RDS(on)is almost certainly because the tester isn't testing with VGS= 10V. Those little testers use 5V, so you'll get the higher RDS(on)of the MOSFET being not fully turned on. Yes, 5V is above the VGS(th)threshold voltage of 4V, but that doesn't mean it'll have reached its lowest RDS(on). The datasheet clearly says that RDS(on)is shown for VGS= 10V, as is typical for non-logic-level MOSFETs.

author: dmulligan
author_rank: Regular Contributor
timestamp: February 01, 2021, 04:02:36 am
content: That makes sense. Q5 and Q6 were also consistent with each other too. Thank you for your help!

author: dmulligan
author_rank: Regular Contributor
timestamp: February 03, 2021, 11:32:18 pm
content: @tooki Thanks again. I now have a working APC XS 1000 UPS.
apollo twin x short circuit - Page 1
Forum section: electronics / repair

author: Userli
author_rank: Regular Contributor
timestamp: August 08, 2023, 01:40:31 pm
content: I received a broken apollo twin x for possible repair and quickly found the device shorted at the 12V input socket.Investigation shows that a component (see image) connecting 12V and GND is shorted. I assume this to be an input protection device but can't find any info about it. Does anybody know, what this is?

author: fzabkar
author_rank: Super Contributor
timestamp: August 08, 2023, 05:16:58 pm
content: It appears to be an SMAJ14A unidirectional TVS diode made by Vishay (General Semiconductor).https://www.vishay.com/docs/88390/smaj50a.pdf

author: Userli
author_rank: Regular Contributor
timestamp: August 08, 2023, 05:58:59 pm
content: That's indeed the most probable and I ordered this one now. I assume though, it's some kind of Chinese clone, since the marking doesn't fit.

author: fzabkar
author_rank: Super Contributor
timestamp: August 08, 2023, 07:22:39 pm
content: It's kinda the same ...https://www.aliexpress.com/item/1005003667874457.htmlThe logo belongs to General Semiconductor which was acquired by Vishay.BTW, it's unidirectional, not bidirectional as I originally wrote.

author: benj38
author_rank: Frequent Contributor
timestamp: August 08, 2023, 07:35:02 pm
content: QuoteWhat part of the marking seems wrong to you?The part number code "XK" is exactly what the datasheet specifies, and the logo seems fine as well.

author: Userli
author_rank: Regular Contributor
timestamp: August 08, 2023, 07:48:13 pm
content: You're right. I looked at the SMC package version, which has a different marking.
Appa 205 / banana plug replacement - Page 1
Forum section: electronics / repair

author: teus
author_rank: Contributor
timestamp: September 23, 2019, 07:37:29 am
content: A few of the banana plugs on this Appa 205 desktop multimeter broke. They need replacement so I'll just replace all of them. I can't find a spare part however. I've spent a few hours trying to look up a service manual, and digging through google/farnell/mouser/... It doesn't look like anything I know. The thread seems to be 3/32" or something 2.3~2.4mm. Anyone got any pointer?Picture attached.

author: shakalnokturn
author_rank: Super Contributor
timestamp: September 23, 2019, 08:19:13 pm
content: Doesn't look like an easy task.You could try asking the manufacturer.If only the the brass part (male thread?) is broken and you are able to remove the remains from the banana, that looks like the spacers used behind tower PC mainboards. Wide thread, not metric.If all else fails you could try tailoring another banana to fit the job, either the inner part of a stackable wire-end banana (male end will need threading to receive a nut) or removing part of or all the plastic from one similar to link below.https://caltestelectronics.com/ctitem/161-safety/CT2236
Apple Duo Dock SMPS low voltage - Page 1
Forum section: electronics / repair

author: elemenoh
author_rank: Contributor
timestamp: December 19, 2021, 10:24:21 pm
content: I have an Apple Duo Dock with a switch mode power supply that has low voltage on the main 12V and 5V rails. 5V is reading about 1.3V. 12V quickly ramps to about 3V and falls back to ~0 in less than a second. It has separate 20V and 5V rails for the laptop inject/eject motor and accompanying switch. Those are okay.All of the electrolytic capacitors have been replaced.The optoisolator has been replaced. It worked briefly after replacement from a known-working PSU, but later went back to the original symptom. The opto works okay in the known-working PSU.The SCR, MOSFETs and voltage regulators tested okay.All resistors tested okay.All diodes on the secondary side tested okay (with a DMM diode test).I tried heating it up with a hair dryer. There was no change.I haven't found any shorts yet. I compared resistance across a bunch of points to the known-working PSU and they were all the same.All of my testing has been with the PSU off and disconnected. I have a DMM and ESR meter. I have a scope, but don't have a differential probe.I'm assuming the issue is on the secondary side somewhere since the 20V/5V rails work okay for the eject motor. But I'm at a loss for what to check next. Any advice?Here's an image of the top side of the PSU.
Apple Quadra 950 PSU - Page 1
Forum section: electronics / repair

author: Daxxin
author_rank: Regular Contributor
timestamp: December 11, 2019, 07:45:02 pm
content: PSU fault some components has terminal corroded and broken like unknown ZD10A who have the schematic can shre it please.

author: iRepairElectronics
author_rank: Contributor
timestamp: December 13, 2019, 09:21:21 pm
content: whats it been soaking in?

author: DaJMasta
author_rank: Super Contributor
timestamp: December 13, 2019, 10:38:04 pm
content: It does look quite grungy.No idea where you can find schematics, but a ZD designator in a power supply has got to be a zener diode used as a reference voltage on the base of a bipolar power transistor - if you can figure out what power rail the transistor drives, you can probably just select the zener of the same voltage to drop it in.Between the grime and the conformal coating, though, I don't envy the repair job...

author: tooki
author_rank: Super Contributor
timestamp: December 15, 2019, 09:21:41 pm
content: I don’t think it’s conformally coated, in the picture it’s just wet with some liquid.

author: tooki
author_rank: Super Contributor
timestamp: December 15, 2019, 09:34:26 pm
content: Also, I think it might be worth considering scrapping the old PSU and replacing it with a modern one. This isn’t horribly difficult to do:http://www.geekdot.com/fix-quadra-power-supply/I’d be hesitant to risk frying a Quadra 950 with a power supply that had corrosion. A carefully modded modern supply seems like a safer bet.
Apple/Philips CRT that died after recap - Page 1
Forum section: electronics / repair

author: Planet Fox
author_rank: Newbie
timestamp: August 17, 2025, 12:50:13 am
content: Have a CRT monitor, an Apple Performa Display which I believe is a rebadged Philips CM2080 or similar, from ca. 1994. I did a recap, but rushed it and solder bridged one of the caps. After clearing the solder bridge, the monitor would turn on, the screen would go totally white, then the overvoltage protection would shut it off once it was warmed up. I put the old caps back, same problem.Thought it might have been some fried silicon, so I replaced the TDA4860 verical deflection power amp, TDA4851 H/V deflection controller, and even the TDA4881 video controller but it's still doing the same thing. Turning the screen control on the flyback down lowers the voltage enough to keep it from turning off, but I'm still not getting a picture; just a washed out gray rectangle with some horizontal lines that move whenever I resize a menu or open a window (see picture).

author: m k
author_rank: Super Contributor
timestamp: August 22, 2025, 01:13:33 pm
content: Which capacitor was shorted, can you find all voltages?Main voltages for CM2080 are 120V and 13.5V that is regulated down to 12V, 9V and 2x 5V.

author: mikeson99
author_rank: Newbie
timestamp: September 24, 2025, 03:25:56 pm
content: Quote from: Planet Fox on August 17, 2025, 12:50:13 amInteresting issue could the constant white/gray screen mean the video signal isn't making it through properly, maybe due to a missing reference voltage or clamped inputs? Have you tried using something likewhite screento send clean test patterns and see if anything changes visually? Might help isolate whether it's a video path issue or still something deeper in the deflection or flyback circuits.
Appliance repairer - Brisbane - Page 1
Forum section: electronics / repair

author: Enlargee79
author_rank: Contributor
timestamp: May 31, 2021, 10:50:49 am
content: Hi all.I reailse asking this here might be a bit of an anathema to the whole group, and I am interstate so there's just no way for me to have a look myself.Anyway, the problem is that there's a heating element failure in my LG dishwasher, which ends the cycle with a HE error and wet dishes, but otherwise generally has completed the cycle until that point. I have done some research and found that a few other issues cause HE errors, including excess water left in the sump after a cycle or sometimes even partly blocked drains. However, I think that it probably is the heating element that needs replacing.My question is, does anyone know of a reputable repairer in the QLD - Logan area, someone that you would hire if you couldn't be there to diagnose or tinker with the device yourself?
AQ8L09U control board - sensor pressure fault leds - Page 1
Forum section: electronics / repair

author: jorgemef
author_rank: Regular Contributor
timestamp: July 18, 2022, 11:17:53 am
content: Hello.I am trying to troubleshoot what can be the cause of sensor pressure fault received that triggers everytime this washing machine flushes. It is a Ariston/Hotpoint with C00298694 control module.The microprocessor inside is a HD64F36079LFZThe pressure sensor is a linear sensor which ranges from 0 to 5V square wave with output of 10,2Hz (with water) to 10,75Hz(flush). Signal attached.I see the microprocessor VCC line with what seems too much riple. It is regulated from an unregulated 12,4v to 3.3v via an LD33.Can the ripple be the source for troubles on the microprocessor, or is in an acceptable level?BR,Jorge

author: jorgemef
author_rank: Regular Contributor
timestamp: August 02, 2022, 05:25:04 pm
content: Well, ripple was only because I was used leads to measure the signal. By using oscilloscope probe with ground spring, voltage regulation seems to be in acceptable range.Will need to check elsewhere if problem persists. Lots of work because of bad measurement/noise from leads.
AR ARS108PSB Powered Subwoofer Repair - Page 1
Forum section: electronics / repair

author: Smoky
author_rank: Frequent Contributor
timestamp: November 15, 2020, 09:32:31 pm
content: What's next to fix is this AR subwoofer. It was built around 2001 and it seems to play pretty well but when it is turned off, a "thump" is heard a few seconds later. There was no signal present at the input of the subwoofer prior to.I'm going to open it up and check if something looks loonyThe first thing I did was measure the load of the 8" speaker. It measures around 4 Ohms. The speaker appears to be in very good condition too:The plate amplifier itself was blanketed with fiberglass insulation. I brushed and vacuumed it out. Maybe, this isn't the type of sound deadening to be using inside of a "vibrating" speakerI turned on the subwoofer while it had no signal being sent to the inputs and I measured ~70mVDC at the speaker terminals using my DMM:I then sent a 20Hz sine wave into the plate amp and my oscilloscope measured a near perfect output from the subwoofer. If I raised the amplitude, I could literally bounce my Hakko soldering iron off of the bench!I'm going to search the web for a schematic and see how the components are arranged. I do see some quality caps like Jun-Fu and G-Luxon inside tooI also made a video of the way the subwoofer acts when it is shut off:

author: jdragoset
author_rank: Frequent Contributor
timestamp: November 15, 2020, 11:19:35 pm
content: Is this a change from when new?The power-off thump does not seem to be very high amplitude to cause woofer damage.Many years ago I had put together some Southwest Technical Products (FET preamps, Universal Tiger amps, Altec Lansing speakers), Had a mega cone excursion when all powered on together but installing an Amperite delay relay with a switching relay to power the amp 10 seconds after the preamp solved the problem.

author: Smoky
author_rank: Frequent Contributor
timestamp: November 15, 2020, 11:30:31 pm
content: I'm not sure Jdragoset, I bought it used. It has probably been stored for some time.What I have noticed too is that the DC Volts at the speaker terminals appears to be dropping the longer it is on. Maybe the capacitors are re-forming themselves? I do recall it being well over 160mV's at the speaker terminals when I first powered it on yesterday.The next time I work on a powered subwoofer, I'll disconnect the speaker from the plate amp and use a dummy load instead

author: mzacharias
author_rank: Frequent Contributor
timestamp: November 18, 2020, 02:42:13 pm
content: The thump at turn-off is probably normal if there is no protection relay. Perhaps even if there is a relay.Most amp protection circuits employ a fast turn-off to avoid thumps of this sort, but it's not required.DC sensing during operation pretty much is.So long as there is no appreciable DC at the woofer terminals during operation, probably nothing to worry about.
Arcade Game Repair: Bad TTL VIL - Page 1
Forum section: electronics / repair

author: Phil Bennett
author_rank: Newbie
timestamp: March 24, 2024, 09:39:36 pm
content: I'm diagnosing a fault with an old arcade game PCB. It is comprised of two PCBs: a 'CPU' PCB and a 'Video' PCB. I don't have complete schematics for either (this was the late 1980s, when companies began to only provide partial schematics for games).One bit of a bus (referred to as MDDB7) is not reaching a valid TTL logic low level:The bus is the lower 8 bits of a V30 CPU's data bus buffered through a 74ALS245. Both components are on the CPU PCB, and with only that PCB powered, I see reasonable logic levels on MDDB7:The ALS245 was replaced with a new, tested-good part. I believe that a component on the Video PCB is pulling up MDDB7 to a dodgy VIL.On the Video PCB, the resistance between MDDB7 and 5V is 81Ω - considerably lower than the rest of the bus. MDDB7 is connected to at least 18 devices, most of which are LS245s but include an HD6445P CRTC and a couple of gate arrays. I don't see any visible shorts between MDDB7 and other signals.Normally when I suspect a bad device on a bus, I'll go around each IC and use my desoldering gun to remove enough solder to disconnect the suspect pin from the bus until the fault subsides. Unfortunately the through holes on this PCB are tiny and this technique isn't working. Short of cutting every suspect pin until I find the culprit, does anybody have any ideas for narrowing down the faulty IC?

author: edavid
author_rank: Super Contributor
timestamp: March 24, 2024, 10:46:23 pm
content: Do you have a 5 or 6 digit DMM? Measure the DC voltage at all the connected device pins. The highest voltage should indicate the culprit.Stopping the CPU and/or adding a pulldown resistor might make this easier, but are not strictly needed.

author: Phil Bennett
author_rank: Newbie
timestamp: March 25, 2024, 01:14:21 am
content: Quote from: edavid on March 24, 2024, 10:46:23 pmI only have a 4.5 digit meter alas. I’ll give it a try nonetheless.

author: Brociall
author_rank: Newbie
timestamp: August 31, 2025, 04:20:01 pm
content: Quote from: Phil Bennett on March 24, 2024, 09:39:36 pmI would recommend trying the local heating/cooling method: sometimes a faulty chip will show itself more strongly when heated with a hair dryer or cooled with a spray, and the level on the bus will start to change.
Arcam A70 SanKen SAP15 transistor trouble shoot - Page 1
Forum section: electronics / repair

author: MartyCan
author_rank: Newbie
timestamp: October 31, 2020, 11:08:45 pm
content: Hi everyone,I'm new here and I'm not an electronic genius, but I've manage to repair a lot of things with logic. So I have that A70 that I purchased new and used mostly as a pre-amp. One year past warranty (of course) while turning it on, it goes red, then shuts off. It has the now known to be problematic Sanken SAP15 darlington transistors. There is no damaged or burnt component unlike some others have experienced. I do not trust the electronic shops around here as they did terrible job on 2 of my deck that I ended up repairing myself. So does anyone here have experience with those Arcam? How do I diagnose those transistors? I hear the transistors are discontinued and a fella here found a way to make new ones fit. Any help is welcome! Thanks in advance!

author: ambrosia heart
author_rank: Regular Contributor
timestamp: November 01, 2020, 02:47:06 am
content: Buy a T4-LCR meter can help you or check by scope with signal inputted and powered the amp section via transformer. See photos.

author: MartyCan
author_rank: Newbie
timestamp: November 01, 2020, 03:48:54 pm
content: That's a nice tool! Does it work with 5 legs darlington transistor as well? I don't have any of these tools, as an amateur, is it worth it to invest in them or should I bite the bullet at this stage and just ship it somewhere to a trusted shop, away from here and hope for the best? I also though that since the transistors are fairly cheap and are known to be problematic, and since there is no sign of "overheating" I could start by replacing them all and see what happens... I was thinking of guetting myself a oscilloscope as it would be handy to find problems on my vintage fuel injection car, would that be any help with this as well? Though?Thanks very much!

author: Audiorepair
author_rank: Frequent Contributor
timestamp: November 01, 2020, 08:48:27 pm
content: I've come across these in the past where the built in Emitter resistor has failed, but the transistor is otherwise good.You can check for this with a multimeter across the appropriate pins.So was able to bodge in an external resistor instead.I don't like these things, just a problem waiting to happen IMHO.
Arcam AVR300 bad caps - Page 1
Forum section: electronics / repair

author: Finderbinder
author_rank: Regular Contributor
timestamp: April 11, 2023, 07:10:24 pm
content: Anyone has a list of electrolytic capacitors (and maybe other components) to be replaced?Just replaced bad caps in main board but I see some bad ones in other boards too. Disassembling it isn't an easy task. Do not want to disassemble it completely and leave so for a long time while I would be acquiring all necessary caps.

author: Finderbinder
author_rank: Regular Contributor
timestamp: April 13, 2023, 12:18:39 pm
content: Now it plays analog audio in Direct stereo mode, but no sound in digital mode. However it detects digital signal when I supply it from DVD player ("Audio" changes to "Digital" when I connect cable with digital sound), but still no sound from speakers.

author: Finderbinder
author_rank: Regular Contributor
timestamp: April 13, 2023, 08:30:58 pm
content: Solved. Issue was with DSP pins - surprise from manufacturer using shitty glue where it shouldn't:
Arcam 'Class-G' Amps - Page 1
Forum section: electronics / repair

author: EHT
author_rank: Frequent Contributor
timestamp: October 28, 2021, 11:16:21 pm
content: Hi, does anyone have a service manual or schematic for the Arcam FMJ A29 integrated amp? The service manuals for the earlier models like FMJ A32 and Diva A85 are great, but I couldn't find the same for this one. I'm not sure which other models are siblings to this one, I guess any "Class G"s.I like the A80/85/90 for the quality of design and build. Not sure if this newer one meets the same!
Are Dallas DS1250 and DS1650 interchangeable in Tektronix Scopes? - Page 1
Forum section: electronics / repair

author: rodd
author_rank: Regular Contributor
timestamp: May 17, 2022, 10:32:16 pm
content: Dear all,I have just seen a video on YouTube where the person says that it is possible to interchange Dallas DS1250 and DS1650 in all Tektronix scopes, since it seems that the protected area is not used by any of the Tek scopes firmware.I have a bunch of DS1650 Srams in my parts bin.Assuming that they are not fake, i might save me some money and the trouble of buying (or building myself) a DS1250 replacement.Can anyone comment on that?Thank you.

author: m k
author_rank: Super Contributor
timestamp: May 22, 2022, 04:27:07 pm
content: They are pin compatible and replaced each others elsewhere.Why didn't you try them?
Are the various flavours of MPC860 device pin compatible - repairing a TDS3054B - Page 1
Forum section: electronics / repair

author: pcarew
author_rank: Contributor
timestamp: January 17, 2023, 05:56:38 am
content: I need to replace an MPC860DEZP50D4 (the main processor) device in a TDS3054B Tektronix oscilloscope.I can't find the DE device anywhere, but I have found a EN device ( MPC860ENVR66D4 ).It is a 'faster version (66Mhz vs 50Mhz) and has 4 Ethernet channels instead of 2 and 4 Serial Communications Controllers instead of 2 according to the H/W spechttps://www.nxp.com/docs/en/data-sheet/MPC860EC.pdf.It seems that all of the 860 devices have the same BGA pinout.What are peoples opinions, can I swap a MPC860EN device in instead of a MPC860DE device?Paul.
Are these cables truly proprietary or can I find them somewhere else? - Page 1
Forum section: electronics / repair

author: Hogwild
author_rank: Regular Contributor
timestamp: May 26, 2022, 03:18:29 pm
content: Hi everyone:I bought some LED lights that I need to link together. The problem is that the manufacturer only offers the 3-prong 110V cable to gang them together in a maximum length of 3 feet. Sure, you can use a box, but in my situation, I'd like to avoid that.The manufacturer swears the connectors on these cables are proprietary, but I could swear I've seen them before.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 26, 2022, 04:41:32 pm
content: i had some battle with theses connectors years ago, i can't remember where i found the ''roundish corners'' version of it, took an solder pen to ''square'' the cornersgood luckoh i do recall some t5 bars have a 3 prong connector rounded corners / molded, not sure if the pins spacing do fit ??maybe something similar ?? you have some physical dimensions on the pagehttps://www.superbrightleds.com/moreinfo/linear-light-bars-general-accessories/pigtail-power-cords-for-t5-linkable-linear-led-lights/3656/?accessory_of=5102-all_accessories

author: Hogwild
author_rank: Regular Contributor
timestamp: May 26, 2022, 05:10:34 pm
content: Thanks for that. I think those are a bit different. I added a second picture, of the other end of the cable, in case that helps.

author: mclute0
author_rank: Regular Contributor
timestamp: May 26, 2022, 09:06:49 pm
content: maybe you are thinking of thesehttps://www.aliexpress.com/item/2251832657521812.html??probably close on the pins but the plastic don't mate.Could maybe fill it in with UV Activated resin? (My favorite new toy after getting teeth filled with it at the dentist)If you are into mods maybe try these I have used before.https://richbay.com.tw/en/product_list.php?sub_id=91but not real safe for humid environs...look over that site as they carry many types.

author: Hogwild
author_rank: Regular Contributor
timestamp: May 26, 2022, 10:08:17 pm
content: Hi:Those first ones you linked to are the same as the ones coromonadalix linked to, just somewhere else.The second one you linked to appears to be standard IEC power, which is wildly different than these.
Array 3645A Power Supply - Page 1
Forum section: electronics / repair

author: dmmguy
author_rank: Contributor
timestamp: November 14, 2022, 09:11:04 pm
content: Hi everybody,Does anybody here knows how to calibrate an ARRAY 3545A power supply.I have downloaded the app but I have not luck connecting the PC with the power supply, I have tried many configs and nothing... it is always saying "communication failed!"I have set the COM5 (USD to SERIAL-TTL) with the same rate (9600) and the address to be 1 in both, the app and the device.Any idea/help??Thanks a lot.
Artesyn LPT42 SMPS repair - Page 1
Forum section: electronics / repair

author: zkrx
author_rank: Contributor
timestamp: April 18, 2024, 03:29:58 pm
content: After 10 years of use, my FAS Axe-FX II died on me. It consists of two boards: an Artesyn LPT42 SMPS that supplies the main board. It had been running fine for 20 minutes when the device turned off right under my nose. The mains fuse blew. I changed the fuse, powered it on again and it blew again immediately.Artesyn LPT42:https://eu.mouser.com/ProductDetail/Artesyn-Embedded-Technologies/LPT42?qs=oQrZyJBXqWGYKAz4i%252BWkOA%3D%3DThe fuse also blows when I disconnect the SMPS from the main board, so it really is the SMPS board that is at fault.Considering a replacement power supply will cost me nearly 100 USD, and that components are only ~1 USD, I am willing to spend a few hours on this. But I don't have a lot of free time. I wondered if someone could tell, from experience, what component would most likely fail, what I should measure first, any tricks I could use to diagnose and fix this quickly-ish.I know that SMPS troubleshooting can be a pain, so I won't be mad if you tell me that I should not waste my time with that.

author: asis
author_rank: Frequent Contributor
timestamp: April 19, 2024, 12:10:13 am
content: Hi,There is a similar PSU.The most vulnerable components are highlighted in red.If you are not completely sure that all components are in good working order, connect the PSU through a household incandescent lamp (NOT LED).

author: zkrx
author_rank: Contributor
timestamp: April 19, 2024, 10:06:33 am
content: Thank you so much. I still have a few incandescent bulbs lying around.Any tip for testing IC1 (3842) or should I just blindly swap & test?

author: asis
author_rank: Frequent Contributor
timestamp: April 19, 2024, 01:42:52 pm
content: If the circuit matches exactly, then check MOSFET Q1 for a source/drain short circuit.Acquire the skill of checking MOSFET's.Release its gate and briefly touch one of the tester's probes to the gate in relation to the source, check the integrity of the structure by swapping the probes, keeping in mind that there is a diode inside the structure.The charge on the gate after touching it remains for quite a long time and you will have time to measure the state of the source / drain transition.Thus, by turning on/off the MOSFET you can verify its integrity.It is possible that the current limiting resistor "R6 0.28E" has burned out.Capacitor C5 (47mF x 50V) is most often the cause of failure due to its degradation under 24 x 7 x 365 operating conditions.In order not to assemble a stand for testing 3842, it is enough to check the state of the internal OUT driver (pin 6) in relation to GND (pin5) and Vcc (pin7).If the structure does not raise suspicions, most likely the IC is working.The feedback loop in this particular circuit monitors +5V and +12V.If the circuit has differences, it is better to do reverse engineering.Everything consists of little things.--Follow safety precautions!
artesyn NLP250R-96S24J - Page 1
Forum section: electronics / repair

author: hitecelec
author_rank: Regular Contributor
timestamp: September 15, 2021, 08:27:41 am
content: hello FolksSMPS with burnt smd component. Does someone have a schematicsthanks in AdvanceRegardsAnand

author: CJay
author_rank: Super Contributor
timestamp: September 15, 2021, 10:15:50 am
content: Post pictures of board and components

author: hitecelec
author_rank: Regular Contributor
timestamp: September 15, 2021, 01:20:47 pm
content: HelloOk. will do

author: hitecelec
author_rank: Regular Contributor
timestamp: September 16, 2021, 10:35:01 am
content: Hi CjayPFAregardsAnand

author: hitecelec
author_rank: Regular Contributor
timestamp: September 16, 2021, 10:39:25 am
content: Hi CjayPFA

author: hitecelec
author_rank: Regular Contributor
timestamp: September 16, 2021, 10:40:55 am
content: Hi CjayPFA

author: hitecelec
author_rank: Regular Contributor
timestamp: September 16, 2021, 10:42:09 am
content: Hi CjayPFA

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 17, 2021, 12:57:21 am
content: If it's not easily fixable, just replace the whole module. 24V power supplies of that size are commonly used in 3D printers.

author: perieanuo
author_rank: Frequent Contributor
timestamp: September 17, 2021, 08:43:46 am
content: the pwm ic is readable, start from his datasheet and put the schematic from your pcb on paper, takes the same time like searching 2 hours for a schematic you may never find (if you didn't get it in 2 clicks, that means you gotta reverse engineer the thing, if you aren't attracted to this goooood idea, just be consumer and buy another one, like others suggestedi vote for reverse engineering, you'll learn morechanging is the last resort for lazu and stu)pid ppl, yep let's throw anything at the bin and buuuuy another

author: perieanuo
author_rank: Frequent Contributor
timestamp: September 17, 2021, 08:49:44 am
content: seems like L4981B pfc chip

author: hitecelec
author_rank: Regular Contributor
timestamp: September 18, 2021, 05:31:26 am
content: Agree. need to take time out and trythanks.
Asix Forte missing some smoke [FIXED] - Page 1
Forum section: electronics / repair

author: Tim S
author_rank: Contributor
timestamp: February 27, 2024, 05:03:24 pm
content: Trying to identify the 6 pin device that spilt it's magic smoke. It's an Asix Forte programmer and is an interface/protection between the FPGA and the programming pins.Case marking is TAR.Thanks,Tim.

author: Tim S
author_rank: Contributor
timestamp: February 27, 2024, 05:53:15 pm
content: ...forgot to add some dimensions.Body is 1.7mm x 1.2mm and it's almost certainly a TVS diode in SOT563 package.

author: Muxr
author_rank: Super Contributor
timestamp: February 28, 2024, 02:30:09 am
content: Looks like a bus transceiver: SN74LVC1T45https://www.ti.com/lit/ds/symlink/sn74lvc1t45.pdf?ts=1709004389974https://e2e.ti.com/support/logic-group/logic/f/logic-forum/906831/i-need-help-to-know-which-parts-are-this

author: Tim S
author_rank: Contributor
timestamp: March 04, 2024, 12:32:16 pm
content: All fixed now, thanks Muxr.Part from Mouser is 595-SN74LVC1T45DRLR for future reference.
ASK Repair of Ryobi BCL14181H Li-Ion charger - Page 1
Forum section: electronics / repair

author: vanhien771354
author_rank: Newbie
timestamp: December 31, 2023, 03:32:42 pm
content: Hi all , i have 2 board Ryobi like picture .https://upanh.tv/image/yXDMhuI have been repair one board, but I dont know result voltage when it working . somebody have Charger please help mehttps://upanh.tv/image/yXDCw3
Asking for +5v, -5v output SMPS repair  - Page 1
Forum section: electronics / repair

author: galaga1982
author_rank: Contributor
timestamp: March 06, 2024, 04:17:33 am
content: Hello?I would like to ask about the 80W, AC 110V input, DC+5V, -5V output SMPS (shindengen CY05010) fault repair.symptoms of a breakdown1. There is no output of +5V voltage. -5V output available and voltage control is possible. If the voltage control volume is raised, the power LED is turned off, resulting in a voltage drop to -1.8V, and if the volume is reduced, it will not recover to its original voltage. (Is it a normal function?) It will be restored only when the power is completely turned off and on.2. It is thought that the output is achieved only when the RC (REMOTE CONTROL) terminal is SHORT, but when SHORT is made, the power LED is turned off and all voltage outputs are not possible.3. The voltage at the output end (+5V, -5V) is SHORT state from the beginning. In order to find out the cause, I tried to separate the capacitor, diode, FET, etc., but it is still SHORT state, and finally, when I separate the 8 ohm cement resistance connected between +5V and -5V, SHORT state disappears. (This is cement resistance that was constructed during the initial design, so this can't be a problem, right?)Attached is the picture, please give me your opinion. I thought it was a simple defect, but it's not easy.Thank you.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: March 06, 2024, 05:11:36 am
content: The drawing on the box does not support the idea it’s a dual rail supply. Did it work as a dual rail supply before?

author: galaga1982
author_rank: Contributor
timestamp: March 06, 2024, 06:29:14 am
content: I'm not sure the exact meaning of the term dual rail supply, but the +5v, -5v outputs seem to work independently.Anyway, I think the short state of +5v, -5v output terminal is abnormal.

author: Jwillis
author_rank: Super Contributor
timestamp: March 06, 2024, 08:59:23 pm
content: Quote from: galaga1982 on March 06, 2024, 06:29:14 amDual rail means that theirs a positive rail and a negative rail in which both voltages are relative to a common ground. +5V to GND (0V) to -5V for example. If and what is used as common ground depends on the circuit. It is possible that it uses the Chassis/Earth ground also as the common ground for the 5V rails. Uncertain unless voltage measurements can be taking. Or its just a weird way of describing a single floating 5V rail.

author: fenugrec
author_rank: Frequent Contributor
timestamp: March 13, 2024, 03:13:15 pm
content: Quote from: Jwillis on March 06, 2024, 08:59:23 pmThat is my interpretation, based on the photos - one single floating 5V supply. User has the option of connecting either V+ or V- to GND, if needed. OP : if you are leaving the outputs floating, you must probe between V+ and V- (unclear if that's what you were doing).The power resistor connected accross the output sounds like a minimum load to keep the supply happy - do not remove unless it's defective.RC, "remote control", seems like a simple on / off control based on drawing on the box.
Asko 200 problems checking control board repair?. - Page 1
Forum section: electronics / repair

author: jimoclark
author_rank: Newbie
timestamp: July 03, 2021, 06:12:47 am
content: Hi all, I have a asko wm200 washing machine. The control board is blowing fuses.I live in North East Pa. on NY Border. Is there anyone in this area that can check and repair my control board? Thanks for your help and connections.When I unplug the drive motor it does not. I replaced the motor but it is still blowing control board fuses. I am at a loss on what the problem is plus have no idea how to go further in my trouble shooting on this. Any advice on what to do would be greatly appreciated. thanks Jim Clark
Asrock H61m-s doesn't activate PSON - Page 1
Forum section: electronics / repair

author: flix27
author_rank: Newbie
timestamp: September 03, 2021, 05:54:01 pm
content: Hi all,my ASrock H61m-s suddenly doesn't power on. No fan spins(including the PSU fan) and no led flashes. The PSU works perfectly on another board. Is it safe to just force power to the board by shorting pson or can I damage something if I do this? Thanks for your help in advance.

author: pcwrangler
author_rank: Regular Contributor
timestamp: September 03, 2021, 07:06:06 pm
content: Sounds like a short. Can you see anything burnt or getting hot?

author: flix27
author_rank: Newbie
timestamp: September 03, 2021, 07:11:28 pm
content: No, after measuring some stuff it just started to work
AstroDesign VG-814 Video Pattern Generator - Page 1
Forum section: electronics / repair

author: NivagSwerdna
author_rank: Super Contributor
timestamp: February 21, 2021, 03:11:40 pm
content: I bought a VG-814 in an auction some time ago and actually now have a use for it.But... it seems this device cannot operate without a set of timings programmed into a front-panel removeable EEPROM and this is sadly missing on mine.I have a replacement EEPROM but need an image to burn into it...Anyone own a VG-814 or similar?Thanks in advance

author: simmconn
author_rank: Regular Contributor
timestamp: February 23, 2021, 06:31:34 am
content: It's your lucky day.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: February 23, 2021, 08:36:39 am
content: Fantastic!Thank you very much.
Asus b34y mother w/ step down  1225c get hot - Page 1
Forum section: electronics / repair

author: marce002
author_rank: Regular Contributor
timestamp: May 11, 2020, 09:44:30 pm
content: Hi allAnyone can give me a tip ... need to know whyThis chip in the laptop motherboard is getting hot.It is a step down 1225c see attachment. This is the only part getting hot as soon as power adapter is pluged in. Does not power on or even turn on leds... 3.3v 5v and 19.8 v are present at random points. A common fault maybe,? Any hint would be much apreciated.
Asus C214M (C241MA-BU0475) starts only when battery is disconnected - Page 1
Forum section: electronics / repair

author: PiotrMisiuna
author_rank: Contributor
timestamp: February 07, 2024, 06:17:52 pm
content: A friend of mine had issue with this laptop not powering on. He watched a youtube video about unpluging battery to reset the laptop and ripped off the connector with the tracks. I bodged a connector on wires to avoid repeating the story. Unfortunately laptop still didn't start. A bit weird behaviour.With the battery connected- If I hit power-on, white LED lits up and goes off.With the battery and power supply connected- If I hit power-on, white LED lits up and goes off.- If I disconnect the power supply and connect it back, white LED lights up and goes off.Without the battery and power supply connected- the orange led lits up and system is booting.I suspected that there is an issue with the battery but now I am not sure anymore. There is a transistor on the battery circuit that gets very very hot, but when I tested it it shows normal readings. Battery cells show normal voltage but there is no voltage on the battery connector when unplugged.Could be something causing excesive current draw on the mainboard that is made accessible only when battery is connected. Resistance of the battery terminals on the mainboard is in Mohms.Laptop has 2 usb-c ports but only one seams to take the power in.Any suggestions as to how to find the fault? is applying voltage on the battery connectors is a bad idea?BTW, I hate how this crap is build, I will never buy anything from asus.
Asus Cromebook C214M: Can I use a generic USB-C charger? - Page 1
Forum section: electronics / repair

author: keerthi123
author_rank: Contributor
timestamp: September 08, 2020, 05:42:43 am
content: I am trying to fix an Asus Chromebook. I don't have the provided charger. Can I use a generic USB-C charger to troubleshoot USB-C powered devices?

author: fordem
author_rank: Regular Contributor
timestamp: September 08, 2020, 04:28:16 pm
content: Probably not - USB-C can supply power at different voltages - 5V, 9V, 15V & 20V - the charger for my ThinkPad supplies all four of these allowing me to connect my Samsung phone to it, but the Samsung charger only supplies 5V & 9V so that it won't power the ThinkPad - it all depends on what the Asus requires.
Asus K501 grèen led flashes error codes - Page 1
Forum section: electronics / repair

author: splin
author_rank: Frequent Contributor
timestamp: October 12, 2019, 05:23:50 pm
content: It won't start up after a wine spillage (powered off in a couple of seconds and battery happened to be disconnected at the time).It's likely a write off but does anyone know the ASUS faultbindication codes? It flashes the battery LED green twice, 1s apart, every 4 seconds.