hybridfree/eevblog-posts huggingface dataset:
RGB Video light Moman MFL-09XR blue leds on even if Power is off - Page 1
Forum section: electronics / repair

author: Uldis
author_rank: Newbie
timestamp: January 03, 2023, 09:24:20 pm
content: Hello and Happy new year to everyone.I am having an odd issue with my portable rgb video light Moman MFL-09XR. Even in an off state the blue LEDs are lit up and won't go off until I completely cut the power source. Once I add power to it it will take a second and the blue light will be back on again (the device is in an off state). Once I turn the device on it does not change the state of the blue led lights so they are still on, but the rest seems to be working fine.I can't find any shorted components but I do hear a buzzing sound. It is hard to work as two boards are connected face to face. Maybe anyone here has some experience or suggestion on what could be the problem here?Thanks!
RGB>LCD conversion -options advice needed - Page 1
Forum section: electronics / repair

author: digsys
author_rank: Unknown
timestamp: August 17, 2019, 12:44:24 pm
content: Just finished a factory repair job - ripping out an old CRT (blew up) and replaced it with an LCD. Picked up a RGB > VGA converter board (the ones that the folks who convert old games machine use), sorted out a few issues, and all works acceptably well. Except for half of the last line of text is cut off (refer pix).The customer doesn't mind, but I'm sort of a perfectionist :-) ... It's been 40+ yrs since I worked on CRTs, so got a bit rusty.Wondering, how much effort to "fix" the problem - hardware? hack the software? (I think some gamers have posted their own "rewritten" code), or do I pay one of them to sort it out? Just looking for ideas -

author: PKTKS
author_rank: Super Contributor
timestamp: August 17, 2019, 02:21:18 pm
content: looks nice.Unless you require that last thing...I would try repositioning the blank pulse to avoid thislast noise things entering the buffer for conversione.g. put the blank pulse a bit earlier to suppress that noise.

author: digsys
author_rank: Unknown
timestamp: August 17, 2019, 11:30:03 pm
content: Quote from: PKTKSThanks for the reply. Well, that's my quandary - a half missing line wouldn't be ideal for the operator, and theycouldlive with the noise option. Wasn't sure if it easier to fix it going the "software hack" method, or a much longer hardware fix. It can hold for now, but with 2 more possible to fix, it was annoying me :-)

author: Rasz
author_rank: Super Contributor
timestamp: August 18, 2019, 05:20:17 am
content: did you press AUTO on the gbs? and on the lcd monitor?you can try clamp options in Geometry menuthen of course is the nuclear option, bypassing buildin microcontroller, can be done with $2 esp8266https://shmups.system11.org/viewtopic.php?f=6&t=52172https://github.com/ramapcsx2/gbs-controlhttps://github.com/ramapcsx2/gbs-control/wiki/Build-the-Hardwareall of this is overkill, because as you and the owner of machine already stated last line is meaningless

author: digsys
author_rank: Unknown
timestamp: August 18, 2019, 08:46:33 am
content: Quote from: RaszYup, fiddled with pretty much every setting, I can get either the top line or bottom line perfect, but not both - one gets cut in half > 2/3. If I shrink V further, all I get is raster / garbage on the last line and rest of screen.I haven't seen those particular links, but did find other users that had made "hackable" code, so another possible option. ThanksQuote from: RaszWell, I hate leaving jobsnearlyok, and I think the owner just wanted his machine back asap. I will sort it out, was just working out what each path involved.
RHODE&SCHWARZ HM0724 signal reading problem - Page 1
Forum section: electronics / repair

author: Alexiis
author_rank: Newbie
timestamp: February 22, 2021, 12:17:20 pm
content: hello, I have a rhode&schawrz hm0724 that can't calibrate or read accurately signals.when trying to calibrate or measure a signal the readings are flickering or jumping all over the screen.I have recently bought it for cheap and I am totally new to oscilloscope. And I want to build a small electronics workshop.I have tried triggering, changing all the settings, and reinitialized it but still having the same issues.And I'm starting to think the problem is internal.Can anyone help?

author: PKTKS
author_rank: Super Contributor
timestamp: February 22, 2021, 01:35:52 pm
content: well depending on how much new... the task is heavy loadStart by trying a service manual to at least familiarize yourselfwith a very complex (and very capable) device ..Try this reference available here on eevbhttp://www.ko4bb.com/getsimple/index.php?id=manualsPerhaps something close helps as wellPaul

author: Alexiis
author_rank: Newbie
timestamp: February 23, 2021, 08:03:51 am
content: Thank you very much PaulI'm looking into that
Rhode&Schwarz SMDV (BN41104) decade frequency standard - Page 1
Forum section: electronics / repair

author: dagema
author_rank: Contributor
timestamp: January 11, 2020, 01:00:42 pm
content: Hi,I own a R&S decade frequency standard SMDV (aka BN41104) which I would like to repair. I have been searching through all the manual links I know of, but I have not been able to find either a service manual or schematicDoes anyone know where I might find some related documentation?Many thanks for any help.
Riden RD6012PW complete kit PSU issue - Page 1
Forum section: electronics / repair

author: codaroma
author_rank: Contributor
timestamp: April 01, 2022, 10:35:30 am
content: Hi all,I'm hoping to get some advice from the forum.I have just purchased a Riden RD6012PW complete kit (bench adjustable PSU, fixed source PSU and enclosure) from RD Official Store on Aliexpress.The fixed source backend is an 800W 65V 12.3A SM PSU.It is the same make and almost the same model of PSU as the one in this youtube video...https://youtu.be/zzW0DvattfM?t=76According to this video this PSU uses a relay to bypass the PTC inrush current limiter after a set time, or a certain voltage is reached across the capacitors.mentioned herehttps://youtu.be/zzW0DvattfM?t=142and herehttps://youtu.be/zzW0DvattfM?t=241I suspect it is a bit like this...from herehttps://www.ametherm.com/inrush-current/ptc-thermistors-for-inrush-current-limitingBUTon my copy of the PSU, the switch side of the relay is not soldered into the board.As you can see in these photos the switch side is sticking up in the air with unconnected pins.This is the underside of the boardThe PSU does appear to be working although I have not put any load on it yet. I suspect if this has a impact on the PSU it would only be obvious at high current loads as the PTC is not being bypassed.My questions are1) Do you think this is intentional or accidental? and,2) Should I try to return it, or just solder the relay back in and hope for the best?cheers

author: TheMG
author_rank: Frequent Contributor
timestamp: April 01, 2022, 05:08:04 pm
content: I can't see any reason such a thing would be done intentionally. Poor quality control or lack thereof is what that is, along with shoddy manufacturing.Solder that sucker down.

author: codaroma
author_rank: Contributor
timestamp: April 05, 2022, 02:13:12 pm
content: Quote from: TheMG on April 01, 2022, 05:08:04 pmMany thanks for your reply. I did exactly as you suggested and its seems to be all work well. Thanks again.

author: luudee
author_rank: Frequent Contributor
timestamp: April 08, 2022, 12:42:00 pm
content: You have probably never attempted to return anything on Aliexpress.They will make you pay for shipping both ways, which will be more expensive than the entire PSU.As other already suggested, try fixing it yourself. Seems a trivial issue ...Good luck,luudee

author: Mr.B
author_rank: Unknown
timestamp: April 09, 2022, 01:32:14 am
content: As TheMG said: Poor quality control.If it had been intentional they would have left the whole relay out to save a dollar.

author: Eheran
author_rank: Regular Contributor
timestamp: April 12, 2022, 08:25:07 pm
content: QuoteI was sent a wrong item once. Disputed it with a picture, said I would be fine with 50 % refund (it was something I could use) but the seller only wanted to give me like 5 €. I then won the dispute and got 100 % of the money back. So there was no need to send anything anywere.Also: Quick shout-out toShayBox and his python libraryto control the PSU. He/We fixed issues with windows, ever since its been running well. Thank you.
Riden RD6024W terrible high noise - Page 1
Forum section: electronics / repair

author: SoundSponge
author_rank: Contributor
timestamp: January 11, 2024, 02:39:13 pm
content: Hi to all..I need helpEvery customer is happy for their unit so I buy one..I buy this unit from Ali but when I purchased I don’t read advertising about high noise without load.. they say it’s normal..Now I want solve the problem in every way is possible.. the noise is unacceptable for me..Hope you can help me!

author: Vovk_Z
author_rank: Super Contributor
timestamp: January 11, 2024, 05:35:58 pm
content: I would recommend a great book:Noise Reduction Techniques in Electronic Systems. Book by Henry W. Ott

author: MathWizard
author_rank: Super Contributor
timestamp: January 11, 2024, 11:34:40 pm
content: So did you look at the output on an oscilloscope ? What sort of noise are you talking about ?

author: SoundSponge
author_rank: Contributor
timestamp: January 12, 2024, 05:46:05 am
content: I don’t have oscilloscope but I link you a videohttps://youtu.be/thYjZ1BGJv4?feature=shared

author: SoundSponge
author_rank: Contributor
timestamp: January 14, 2024, 01:29:55 pm
content: AliExpress suggest to put 5.1 kohm resistor (higher than 3W) at output.What do you think about this solution?

author: unseenninja
author_rank: Regular Contributor
timestamp: January 14, 2024, 06:05:55 pm
content: It seems you don't mean electrical noise, but fan noise.The resistor you are talking about goes in the power lead to the fan to slow it down. Do that, or fit a Noctua fan instead.

author: SoundSponge
author_rank: Contributor
timestamp: January 15, 2024, 08:48:43 am
content: It's not a fan problem, its high frequency noise probably from power supply. Yes it's electrical noise. See my video 2 message upper In this chat

author: SoundSponge
author_rank: Contributor
timestamp: January 16, 2024, 08:06:36 am
content: From RIDENDue to the large output power range of the product, in order to reduce the power consumption of the switching power supply when no-load, the PWM control chip will jump some control cycles. Assume that the original working frequency is 60KHZ. If there are more skipping cycles, the working frequency will be reduced to less than 20KHZ. This Sometimes a noise audible to human ears is produced. The size of this noise is also related to the production process of the transformer. Since the winding and paint impregnation of each transformer’s coil are slightly different, the noise of each product’s operation is slightly different.

author: SoundSponge
author_rank: Contributor
timestamp: January 18, 2024, 05:58:06 pm
content: Any help for me?
Rifa Boom Help! - Page 1
Forum section: electronics / repair

author: mictas
author_rank: Regular Contributor
timestamp: July 05, 2025, 07:15:23 am
content: Hello everybody whom reads this.I picked up a junked Bernina 420 sewing machine and found the power cable cut, mechanically it seems fine and needs a clean up. Being that it was only $15 AUD I took the chance on it and once home opened up the foot pedal to see the bloody Rifa with its side blown out...I have the suspicion I found the cause of the power cable (foot pedal) failing the PAT test and am just not 100% sure if I found a compatible replacement, so I have come here to confirm things.The broken cap has the following details:QuoteAnd here I have the two that look like they might be a good replacment:https://au.element14.com/panasonic/ecqubaf104ka/cap-safety-0-1uf-class-x1-300v/dp/3550479https://au.element14.com/roxburgh-emc/xe1201/cap-0-1uf-250vac-0-5w-120-ohm/dp/1187649

author: indeterminate
author_rank: Regular Contributor
timestamp: July 05, 2025, 09:05:17 am
content: The Panasonic would be fineor if you wont one fasterhttps://www.jaycar.com.au/100nf-250vac-metallised-polypropylene-x2-capacitor/p/RG5236

author: wraper
author_rank: Unknown
timestamp: July 05, 2025, 09:19:08 am
content: Any 0.1uF X2 or X1 capacitor of appropriate size will be fine.QuoteIt's a snubber capacitor with a built-in series resistor.

author: mictas
author_rank: Regular Contributor
timestamp: July 05, 2025, 10:02:08 am
content: Quote from: indeterminate on July 05, 2025, 09:05:17 amI was really, really hoping the Panasonic one would be good.Jaycar, I kind of want to stay far away from that place, plus it will be some time before I'll be working on this sewing machine.Thanks.Quote from: wraper on July 05, 2025, 09:19:08 amFunny, you should say that, because hidden under the Rifa, there is a resistor.

author: Gyro
author_rank: Super Contributor
timestamp: July 05, 2025, 11:57:00 am
content: Quote from: mictas on July 05, 2025, 10:02:08 amI can't read the colour code but I suspect that is a high value resistor, in parallel with the cap, to discharge it and prevent a shock risk when the plug is removed.
RIFA capacitor replacement - Page 1
Forum section: electronics / repair

author: maeshlmaent
author_rank: Newbie
timestamp: September 12, 2024, 11:34:26 am
content: Hello everyone,I have two old rifa caps in a snubber circuit(I guess). I couldnt find any document about them, please can you advise me modern caps instead of these rifas.

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 12, 2024, 11:57:39 am
content: Safety film capacitors. Rated X2 or Y2 depending on whether they are L - N or L/N - EARTH/CHASSIS.

author: madires
author_rank: Super Contributor
timestamp: September 12, 2024, 12:06:54 pm
content: If no safety caps are required you could use Wima MKP series.

author: wraper
author_rank: Unknown
timestamp: September 12, 2024, 12:08:29 pm
content: Quote from: Ice-Tea on September 12, 2024, 11:57:39 amThese are not safety caps. Rifa made multiple series of that garbage. They can be replaced with regular polypropylene capacitors. Polyester should be fine too in most cases.

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 12, 2024, 12:15:36 pm
content: They are most often found on primary side, including filters etc. I stand by my recommendation.

author: wraper
author_rank: Unknown
timestamp: September 12, 2024, 12:20:42 pm
content: Quote from: Ice-Tea on September 12, 2024, 12:15:36 pmSafety versions are marked as such. You don't need safety capacitor for snubber.https://file.elecfans.com/web1/M00/20/FE/ooYBAFmk4f2AOsh6AFozsxcyW-I075.pdfQuote

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 12, 2024, 12:40:06 pm
content: I stand corrected. I'll rephrase to "Safety film capacitors. Rated X2 or Y2 depending on whether they are L - N or L/N - EARTH/CHASSIS. Unless you're 100% sure a safety rating was not part of the original part or should have been given the application" ;-)

author: factory
author_rank: Super Contributor
timestamp: September 12, 2024, 12:54:06 pm
content: The pictured parts are DC rated interference suppression capacitors, i.e. PME261 from this pdf.David

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 12, 2024, 12:58:42 pm
content: Yeah, wrapper provided a pdf as well. Hence me grudginly admitting I may have been not 100% correct and modifying my original statement in the most minimalistic way possible

author: Gyro
author_rank: Super Contributor
timestamp: September 12, 2024, 07:21:50 pm
content: Quote from: wraper on September 12, 2024, 12:08:29 pmThe USP of metalized paper capacitors like the Rifas is high dV/dt capability. Polypropylene would be the safer (in terms of longevity) replacement choice of the two.
Rifa Madness - Page 1
Forum section: electronics / repair

author: ArthurDent
author_rank: Super Contributor
timestamp: May 15, 2019, 07:21:34 pm
content: I have replaced a number of the IEC filters in older HP equipment before there was any explosion and mess in the unit they were in. Today I was load testing an HP bench power supply and all of a sudden there was a loud 'snap' and the magic smoke billowed out of the top of the supplyThe supply didn't have one of the notorious IEC filters but it did have one of the exploding Rifa capacitor across the line that had popped. Fortunately it wasn't sealed inside a IEC filter or the report would have been much louder. There was no black goo and the power supply will look like new once a replacement capacitor is installed. Here are a couple of photos and you can see how the plastic case has cracked all over and apparently this lets moisture in and eventually the capacitor shorts out.

author: Gyro
author_rank: Super Contributor
timestamp: May 15, 2019, 07:39:03 pm
content: Yes, old Rifa metalized paper cap cracking and moisture ingress failure comes up a lot around here!
RIFA X2 with integrated 220 Ohm inrush - Page 1
Forum section: electronics / repair

author: cybermaus
author_rank: Frequent Contributor
timestamp: November 16, 2021, 05:53:58 pm
content: HI guysI have some equipment with RIFA X2 that did not yet burn but does have cracksObviously I want to replace themProblem is: these have integrated inrush 220 Ohm inrush resistorsOn the photo, you can see the resistor inside the resin on the side.And I want to avoid pitching a separate resistor and capacitor against each other each with one leg in the air.Especially since this is a mechanical device, with plenty of vibrations.But I am not sure how to even search for that in DigiKey or FarnellWho can give me some search terms or tips or model names?Specifically, these are 0.22uF X2 500V 220 Ohm with 22mm leg spacing.They are on a mounting board where leg spacing is not very critical

author: rsjsouza
author_rank: Super Contributor
timestamp: November 16, 2021, 06:33:15 pm
content: This should be suitable:https://www.mouser.com/ProductDetail/KEMET/PMR209MC6220M220R30?qs=ffqAhwBssBsrOoIR2iXGlw%3D%3D
RIFA's hiding everywhere! - Page 1
Forum section: electronics / repair

author: Aviotronix
author_rank: Newbie
timestamp: February 11, 2020, 08:11:55 pm
content: Getting a 40 year old Dual turntable up and running and what do you know.... there they are just waiting to go pop!

author: pcmad
author_rank: Regular Contributor
timestamp: February 12, 2020, 02:21:05 am
content: ...

author: floobydust
author_rank: Super Contributor
timestamp: February 12, 2020, 04:51:55 am
content: Just put in new onesRifa/Kemet PME271vintage TT I put in Wurth parts, and ensure there's a fuse. Last Thorens did not have one.

author: TerminalJack505
author_rank: Super Contributor
timestamp: February 12, 2020, 05:11:30 am
content: I've got a Tektronix 2467 oscilloscope with all the original caps. It's no surprise that the Rifa caps are nice and cracked. I'm on the fence about whether to re-cap it or just sell it and let someone else bother with it.

author: Aviotronix
author_rank: Newbie
timestamp: February 12, 2020, 03:03:34 pm
content: Floobydust, that’s the plan except I’m using Wima caps.

author: wiesl
author_rank: Contributor
timestamp: March 16, 2021, 02:46:46 pm
content: Replace that old cracked Caps as fast as you can ...

author: giacomo
author_rank: Regular Contributor
timestamp: March 17, 2021, 08:59:41 pm
content: They are installed as part of the emi filterYou should replace the capacitor between line and neutral with X type capacitors and the capacitors between line and ground and between neutral and ground with Y capacitors.Those types are sold (on mouser for instance) as "safety capacitors".

author: EHT
author_rank: Frequent Contributor
timestamp: March 17, 2021, 10:42:21 pm
content: I gather thePME271have good characteristics when they haven't failed (!) so maybe replacing them with new PME271s is OK. I wonder if Kemet have improved the resin so it doesn't crack?Also I suppose caps that don't look cracked are probably OK although i've replaced any that i've found. Usually they have cracked in equipment that is 20-30yo.

author: tooki
author_rank: Super Contributor
timestamp: March 18, 2021, 07:41:29 pm
content: Quote from: Aviotronix on February 11, 2020, 08:11:55 pmI have a couple of unused, but cracked just like in the picture, RIFAs sitting in my drawer at work. We've been meaning to go outside and apply mains to them and see if anything happens...

author: Gyro
author_rank: Super Contributor
timestamp: March 18, 2021, 08:22:39 pm
content: Probably nothing - they're sneaky little buggers - they lurk and fire up when you least expect it.Quote from: EHT on March 17, 2021, 10:42:21 pmYes, they have better dV/dt withstand capabilities than plastic film types.
Right-hand side of 2 meter LED-scroller-panel is flickering. RHX-8Q2#AP [fixed] - Page 1
Forum section: electronics / repair

author: htm
author_rank: Regular Contributor
timestamp: September 25, 2024, 08:02:57 pm
content: Hi,i've bought a 2 meter LED scroller 2nd hand.The (tiny) contollerboard says RHX-8Q2, just like the WIFI AP name.it is built up with 2 rows of "P10RGB-3535-S4-V3" panels.The left and right side are both powered by separate 5V 40A power supplies.When i have a bright image showing,i can clearly see the whole right hand side(where all data is flowing towards) flickering more.Here's a video of the effect:https://odysee.com/@000_Playlist_misc:4/49482c52a6d02d5882376c8a4e7753c63044851b_8915023710242285:2Also, what is not showing in the video, but can be seen in the 2nd attached picture, is that when images is filling the screen,there are pixels lighting up (like static noise but in spicific columns) where they shouldn't be.in the attached picture you can see the power arrangement. in the picture, it's the far side of the panel which is flickering.i'm guessing it's the power supply.(but i wouldn't know how to check)What would you suspect to be the cause?

author: Bryn
author_rank: Regular Contributor
timestamp: September 26, 2024, 06:14:24 am
content: Quote from: htm on September 25, 2024, 08:02:57 pmI believe you are most correct about that, especially if it's not giving the adequate voltage and current as specified for the LED panel itself (so you would need to check that).If you have any spare power supplies, test with them and see if they give the same result.

author: htm
author_rank: Regular Contributor
timestamp: September 28, 2024, 07:21:46 pm
content: The vertical-noise lines and flickering on the right side is gone!🎉Because i received the replacement 5V 40A power supply, so i opened it up to panel,set up the full white test-pattern, i measured 4.95 voltage on both power supplies.wanted to connect both 5V supplies to scope to see if they show the same pattern, buti found some metalic debris parts inside the panel😲 got rid of it.(Oh. The 220 power cord was connected to the 1st power supply. And a cable looped to the 2nd power supply, but was connected wrong-way ruound to the 2nd power supply. So i corrected it.)Then i set up the white text,and now the vertical noise patterns in the right side is not there.So i think either it was debris, or the power cord to the second panel didn't have a solid connection.Now i guess i've a new 5v power supply left over
Rigol DG1022 function generator completely dead  - Page 1
Forum section: electronics / repair

author: Daveedius
author_rank: Contributor
timestamp: October 04, 2022, 06:15:40 pm
content: I recently purchased a function generator from ebay that's completely dead. After doing some probing around on the PSU, I discovered that the bridge rectifier is working properly but the obsolete half-bridge LLC controller (TEA1610T) has a short of 3.5 ohms between the high gate driver pin and its Vdd pin. Unfortunately I don't have a differential probe and I'm not overly familiar with power supplies, so I'm kind of limited in what I can check. But before I order the obsolete chip from China, I have some questions.1. Any idea what could have caused this?2. Are there any other chips that should be replaced and/or checked? I was thinking the two mosfets might be good practice but I don't know for sure3. Does anyone have any schematics for this PSU or a similar one?4. Does anyone have any information on how these Rigol PSU's work? It seems like there's some signal wires coming from the logic board but I'm not sure

author: Gyro
author_rank: Super Contributor
timestamp: October 04, 2022, 06:35:29 pm
content: You should definitely check the mosfets for Drain-Source shorts (probably Gate-Source too). Also check any diodes - including the secondary side rectifiers, even though the PSU should be protected, they would cause an overload.You might be safer sourcing the replacement TEA1610T from Europe rather than China, it's an NXP / Philips part and you are hopefully less likely to get a fake part!
Rigol dg1022, sucsessful  "no output on channel one Repair" - Page 1
Forum section: electronics / repair

author: NikoJu
author_rank: Newbie
timestamp: October 01, 2019, 08:25:30 pm
content: Hi everyone!I was given a broken Rigol dg1022 arbitrary waveform generator whiches main output (output one) didn't output any signal.When running the self-test with output one turned on it reported something like "overload protected channel one turned off".After some testing, I narrowed the problem down to a shorted common mode choke on the output circuitry of channel one.I did some research and found that the original common mode choke by TDK (ACM3225-601-2P-T001) is obsolete and can't be bought anywhere.I could, however, find a perfect/even better, pin-compatible replacement for it which is also produced by TDK - (ACP3225-102-2P-T000).https://www.digikey.de/product-detail/de/tdk-corporation/ACP3225-102-2P-T000/445-8637-1-ND/3024968As I saw quite a few forum posts about repairing the dg1022 waveform generator and it took some time to find useful information myself, I thought this information might be helpful for someone out there trying to repair their waveform generator.I hope I could help someone with this information!have a great day!Nikolaus

author: Pulsepowerguy
author_rank: Regular Contributor
timestamp: November 10, 2021, 02:05:26 am
content: Thank you! I found the same problem with mine.

author: lern01
author_rank: Regular Contributor
timestamp: July 20, 2025, 02:30:12 pm
content: Wouldn't it be better to use ACP3225-601-2P-T000?
RIGOL DG1022A  - help with low output level - Page 1
Forum section: electronics / repair

author: gpaJoe
author_rank: Newbie
timestamp: August 12, 2023, 03:29:43 pm
content: I just purchased a used RIGOL DG1022A. It powers up and the display appears to be operating normally, and all waveform options appear to be operating on the display. However, the output level of the generated signals are extremely low, like in the 10-15 mV range, regardless of the amplitude level setting. This is true for all waveform selections. I'm feeding this signal into a RIGOL DS1202Z-E oscilloscope. Selecting High-Z or 50-ohm has no effect. Does anyone have an idea of what the issue might be, or the faulty component that might be causing this behavior? I am also looking for a schematic for this unit--any suggestions for a source? ...Thanks for any help you can provide.

author: bingo600
author_rank: Super Contributor
timestamp: August 13, 2023, 06:15:32 pm
content: Maybe this will help - They fix an opamp herehttps://www.eevblog.com/forum/repair/rigol-dg1022-attempted-repair-%28and-reverse-engineering%29/msg950961/#msg950961Some coilhttps://www.eevblog.com/forum/repair/need-help-for-a-repair-for-the-rigol-dg1022a/msg2274588/#msg2274588

author: gpaJoe
author_rank: Newbie
timestamp: August 14, 2023, 12:59:25 pm
content: Thanks! I'll check it out.

author: MathWizard
author_rank: Super Contributor
timestamp: August 16, 2023, 12:56:26 pm
content: I'd check the output transistors, see if their Vcc seems ok, and if their Vbe makes sense.

author: gpaJoe
author_rank: Newbie
timestamp: August 16, 2023, 08:17:56 pm
content: Thank you. I'll do that.
Rigol DG1022Z not booting, slow bootloop.  Is there a service manual? - Page 1
Forum section: electronics / repair

author: richtoy
author_rank: Newbie
timestamp: February 11, 2025, 10:58:12 pm
content: Hi,My little used Rigol DG1022Z has stopped booting. There was nothing connected, it had started and I was setting a some values when it just rebooted. It came back and then the same thing happened. This has continued and now it occasionally shows the initial boot screen and a couple of progress dots before again resetting.I opened it, all PSU voltages on the main supply and the 4 regulators on the main board are ok for voltage and ripple.However, there are more voltage test points near the processor labeled "Power ARM" and three of these (3.3v, 1.8v & 1.5v) have synchronised noise on them.Is there a service manual? Any suggestions as to where to look further?
Rigol DG5072 two channel function generator, ch1 attenuator fault - Page 1
Forum section: electronics / repair

author: Bjoern
author_rank: Contributor
timestamp: October 29, 2023, 07:13:38 am
content: I got this waveform generator with a faulty attenuator at channel 1.I can see the waveform with the correct frequency but also a DC offset.I am trying to figure out why ch1 is not working properly.The output transistor measure OK.I am not sure which OPamp is the direct driver of the output transistors.One of the 10pin SMD chips from Analog Devices is marked D 0M, i am not sure what that isbut I can measure a sine-wave on the working ch and none on ch1.If someone could point me in the right direction would be very helpful.Highly appreciated!

author: Swainster
author_rank: Frequent Contributor
timestamp: November 01, 2023, 08:23:01 am
content: Hi Bjoern,I don't have any experience with this model AWG but my google fu says that 10 pin Analog devices IC is a digital potentiometer AD5243BRM10 - hope that helps a bit!BTW, did I buy a Chroma DC load from you on Carousell, may be about a year ago? Can't be many Bjoerns in Singapore...

author: Bjoern
author_rank: Contributor
timestamp: November 01, 2023, 08:38:02 am
content: Hi, thanks for your help. I cant remember selling a DC load on Carousell but several other things so we might have met :-)
Rigol DHO804 front glass replacement — possible to fix without replacing full LC - Page 1
Forum section: electronics / repair

author: GNUES
author_rank: Newbie
timestamp: August 13, 2025, 10:16:54 am
content: Hi all,I have a Rigol DHO804, and the front glass over the LCD/Touch screen got chipped from an accidental knock.I’m wondering if anyone has taken apart this series and can tell whether the front glass is a separate protective layer, or if it’s bonded (full lamination) to the LCD/touch panel，which need special devices to remove the glass from the screen.Any teardown photos, part numbers, or repair experiences would be greatly appreciated. I’m fine with doing careful disassembly if it’s possible to separate the glass without destroying the display.Thanks in advance!

author: sprit
author_rank: Regular Contributor
timestamp: August 21, 2025, 06:00:14 am
content: Hi GNUES,Use a glass separator and drop it on the black outer edge. I don't know what it's called in your country but it's the type to separate the glue from the phone screen, you can go to the phone repair area and ask them about the solution. Then you can separate the screen layer. There's another touch panel on top of the screen, it's a separate component.Best regards,Feng
Rigol dho804 unboxing and does not boot - Page 1
Forum section: electronics / repair

author: ahmedfotoh
author_rank: Contributor
timestamp: May 09, 2025, 09:53:41 pm
content: I just bought a Rigol Dho804 Oscilloscope, when I unboxing and turn on the display stays appears Rigol logo and still appear to 5 minutes until a message appears to reopen application and no boot to the operating system, and no something until I turn off, and repeat the same thing, I use the original power adapter came with scope.What should I do?

author: tom66
author_rank: Super Contributor
timestamp: May 09, 2025, 11:22:27 pm
content: If it is brand new, should you not contact the seller? It should have a warranty. Probably the firmware is corrupted, there are recovery methods if the warranty is no good.

author: ahmedfotoh
author_rank: Contributor
timestamp: May 09, 2025, 11:32:52 pm
content: Thank you for reply, I from Egypt and bought it from China, I ask for if there is any something to do to reset the firmware before I send it China supplier to repair "the scope هis under warranty in China" because I bear the cost of shipping from EG to CH and and vice versa.
Rigol DL3021 Screen Crash - Page 1
Forum section: electronics / repair

author: maxpayne
author_rank: Regular Contributor
timestamp: July 22, 2019, 09:01:24 am
content: Dont know what happened. I powered it up, it ran for a while and then suddenly the screen became full of vertical bar and eventually dead. It seems functions are ok, as I can hear the buzzer, LED lits while selecting option with knob and button.Is the LCD used really that bad quality that it died after couple of use ?

author: coromonadalix
author_rank: Super Contributor
timestamp: July 22, 2019, 10:21:20 am
content: Is it under warranty ??If not maybe you could poke inside to see if the lcd ribbon maybe disconneted in a way, or not aligned correctly in the connectors ??

author: maxpayne
author_rank: Regular Contributor
timestamp: July 22, 2019, 10:23:55 am
content: It is solved now ....I lifted up the machine around 3 inch and dropped it . actually gave it a hard jerk !!and its ok now !Probably the ribbon connection is loose. I will open it and fix itThanks

author: Dino KL0S
author_rank: Contributor
timestamp: July 23, 2019, 01:10:30 am
content: First rule of troubleshooting...pick it up a few inches and drop it!

author: coromonadalix
author_rank: Super Contributor
timestamp: July 23, 2019, 01:53:54 am
content: Thats maximum payne loll glad it worked in a way
RIGOL DM3051 burned ic please help to identify - Page 1
Forum section: electronics / repair

author: architectus21st
author_rank: Newbie
timestamp: September 16, 2020, 11:13:37 am
content: Hi.ic marked: JDVAK or J0VAKon pcb it is U603TSSOP08 propably package.Please help to identify this icThanks in advance

author: fzabkar
author_rank: Super Contributor
timestamp: September 16, 2020, 07:37:43 pm
content: JD = ECH8605 dual MOSFET

author: architectus21st
author_rank: Newbie
timestamp: September 17, 2020, 05:56:41 am
content: Thanks but i do not think it is this element.all pins of this ic goes to different components... no .pins.8 pin goes to big ceramic capacitor it suggest that is power....7 pin goes to vias to another side of pcb ...Seeking still ...

author: architectus21st
author_rank: Newbie
timestamp: September 17, 2020, 06:38:59 am
content: Picture and marked ic in circle.It is screenshot taken from this thread:https://www.eevblog.com/forum/reviews/rigol-dm3051-5-34-digit-multimeter/3# picture from topI do not have camera here cant make picture.on ic in one line is: JDVAKnothing else at bottom ic or second lineone string no spaces.no logo

author: goaty
author_rank: Regular Contributor
timestamp: September 17, 2020, 08:21:14 am
content: Last picture cropped and rotated, but still can´t make out more

author: fzabkar
author_rank: Super Contributor
timestamp: September 18, 2020, 12:30:11 am
content: You're not helping us ...How about this?AAT3190, Skyworks, Positive/Negative Charge Pump for Voltage Bias, 2.7V to 5.5Vin, marking JDxyy, MSOP-8:https://media.digikey.com/pdf/Data%20Sheets/Skyworks%20PDFs/AAT3190.pdf

author: Chris56000
author_rank: Frequent Contributor
timestamp: September 18, 2020, 02:52:57 pm
content: Hi!I would say, going from the position of U603 generally near the power supply electrolytics, etc., that Member Fzakbar has hit the nail on the head!The OP has nothing to lose by trying one of these AAT3190 devices in the DM3051 – I did have a firmware–bricked DM3058 a while back but pocket–money shortages forced me to pass it on, so I can't offer any better pics myself I'm afraid!Chris Williams

author: architectus21st
author_rank: Newbie
timestamp: September 20, 2020, 12:26:00 pm
content: i will post picture at monday.Schematics a this AAT3190 maybe pass....GND is on correct pin and there also connected SOT-23 elements...I seek where to buy this aat :-(In EUROPE

author: fzabkar
author_rank: Super Contributor
timestamp: September 20, 2020, 06:53:34 pm
content: Before replacing the IC, I would first verify that there is no short on either output.
Rigol DP1308A Power Supply - Page 1
Forum section: electronics / repair

author: DemasPPC
author_rank: Newbie
timestamp: August 22, 2024, 03:25:43 pm
content: Hi, I'm looking for a calibration manual for this power supply or a password to start calibration

author: thm_w
author_rank: Super Contributor
timestamp: August 22, 2024, 11:42:55 pm
content: Nothing herehttps://www.manualslib.com/manual/686673/Rigol-Dp1308a.htmlTry 1111 or 11111.Maybe 2009 or 2011 too. The DP832 password was 2012.

author: DemasPPC
author_rank: Newbie
timestamp: August 23, 2024, 01:59:43 am
content: These codes don't look like, 12345, 1234, 1111-11111111, 2000-2024, 0000-00000000

author: bombcat
author_rank: Contributor
timestamp: September 12, 2024, 08:05:41 am
content: password 666666如果想要校准，只需要一个5 1/2或6 1/2精准的万用表。

author: thm_w
author_rank: Super Contributor
timestamp: September 12, 2024, 10:32:21 pm
content: Quote from: bombcat on September 12, 2024, 08:05:41 amQuoteThank you.Though please translate your future posts to english as this is english forum.

author: Smokey
author_rank: Super Contributor
timestamp: September 13, 2024, 12:50:57 am
content: Quote from: bombcat on September 12, 2024, 08:05:41 amQuote

author: bombcat
author_rank: Contributor
timestamp: September 14, 2024, 09:21:22 am
content: OK！I try to translate it , but it's not always accurate.

author: DemasPPC
author_rank: Newbie
timestamp: October 02, 2024, 05:27:56 am
content: Thank you all, unfortunately I couldn't check this code. I don't have this block at hand now, but I am very grateful to you and glad for your help
RIGOL DP711 blown output protection diode - Page 1
Forum section: electronics / repair

author: luke44
author_rank: Newbie
timestamp: December 27, 2022, 03:30:08 pm
content: Hello,I managed to blow the output protection diode (user error, don't ask) on my new RIGOL DP711 - 30V 5A.As the component is partially destroyed the reference is only partially readable.Anyone can help with the specs of this diode?Thanks

author: beatman
author_rank: Regular Contributor
timestamp: December 27, 2022, 03:53:13 pm
content: i open mine psu and see what number code is

author: beatman
author_rank: Regular Contributor
timestamp: December 27, 2022, 03:57:44 pm
content: NFK51G-B1045

author: fzabkar
author_rank: Super Contributor
timestamp: December 27, 2022, 05:20:52 pm
content: MBR1045:https://www.onsemi.com/pdf/datasheet/mbr1035-d.pdf

author: luke44
author_rank: Newbie
timestamp: December 27, 2022, 06:15:03 pm
content: Many thanks for the replies beatman, fzabkar.So this would be a 45V, 10A Schottky Barrier Rectifier made by Onsemi.Thanks a lot!
Rigol DP711 Fan errror - Page 1
Forum section: electronics / repair

author: tibimakai
author_rank: Contributor
timestamp: December 22, 2023, 03:10:27 am
content: I have picked up this power supply for free(it was scrapped at my workplace, actually two of them)After turning it on, comes up the fan error message, and the output is disabled because of it.Also got another one, with the positive binding post broken off. Otherwise it works great.Switched all three PCBs between them, but error is still there. So I'm assuming it that must be a software issue.Anybody encountered such an issue before?I can't seem to find that binding post either.It is custom made by Rigol?Any help would be appreciated.Tibor

author: FIXITNOW2003
author_rank: Regular Contributor
timestamp: December 22, 2023, 07:10:31 am
content: some notes here on fans and a bit off circuit different model number but may helphttps://www.eevblog.com/forum/projects/fan-replacement-on-the-rigol-dp832/

author: tibimakai
author_rank: Contributor
timestamp: December 22, 2023, 08:43:12 pm
content: Thanks, but mine does not even turn on properly.That thread may help in the future, when I manage to revive it first.There is a way to reset it, or do a forced firmware update? I know that a firmware is not available. Maybe somebody has a dump?

author: tibimakai
author_rank: Contributor
timestamp: December 25, 2023, 09:02:28 pm
content: Nobody has any ideas what to do with this power supply?
Rigol DP712 failed for no obvious reason - Page 1
Forum section: electronics / repair

author: AndersJ
author_rank: Frequent Contributor
timestamp: July 10, 2020, 04:41:27 pm
content: The power supply suddenly failed while delivering 24V at 100mA.It displays "Analog board failed in self-inspection".Any ideas?Sorry about the image size and orientation.I am unable to shrink it, or rotate it.Maybe I am too stupid to own a Rigol.

author: Akai
author_rank: Newbie
timestamp: August 26, 2024, 07:49:34 pm
content: HelloI also have a DP711 with the same error, the text comes up immediately when switched on.Have checked what I can check, +14V, -15V, Rectifier, OP Amplifiers etc..One might suspect "CHIPSEA" CS1232 (Analog to Digital Converter)Can these have a "service menu" where you can go in and see and test functions manually?
RIGOL DP811 Value of current sensing resistor position R52 On circuit (Burned) - Page 1
Forum section: electronics / repair

author: cidak
author_rank: Unknown
timestamp: January 18, 2024, 05:13:55 pm
content: Hi everyone.Big thanks in advance to the people who can help solve my repair problem on RIGOL DP811 (SINGLE OUTPUT 20v/10a 40v/5a).I stupidly turned off the power supplywhile a charging battery was connected to the output.This incorrect operation caused an SMD current detector shunt resistor to burn out.I can no longer read the valuebecause it has burned out...Can anyone check its value on their power supply, or indicate and/or provide me with the electronic diagram with part list of components of the DP811.The position on the printout is R52.I found some photos of a teradown of DP832, (the value is 0.020 Ohm) But the value used by Rigol on DP811 is different.I can't read the value because the current detector resistor has burnt out. Who can kindly help?Spending $1000 on a new power supplyfor a stupid $2 resistor is crazy.Help!!!Thank you

author: Vovk_Z
author_rank: Super Contributor
timestamp: January 18, 2024, 10:31:17 pm
content: IDK, if 832 model being 3 A rated has 0.02 R shunt then 5-10 A rated 811 model may have 0.01 R or 0.005 R shunt. You may try use one of these values and see how it goes.
Rigol DP811/DP832 backlight repair - Page 1
Forum section: electronics / repair

author: R-1125F
author_rank: Regular Contributor
timestamp: October 23, 2022, 02:17:01 pm
content: I am repairing a Rigol DP811 power supply (single channel version of the DP832) that has a LCD backlight problem. I think the boost converter chip is bad. The problem is that I can't identify the exact chip type. The chip is labeled GJFJ. I can't cross reference this code to anything that makes sense. The supply voltage is 3.3V and the output should be about 19.2V to drive 6 white LEDs in the backlight.Could someone identify the part number for this chip?

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: October 23, 2022, 03:56:33 pm
content: Looks like Richtek RT9261A in its SOT23-5 version.https://www.richtek.com/assets/product_file/RT9261=RT9261A/DS9261A-16.pdfDouble check if the pinout matches the board.

author: R-1125F
author_rank: Regular Contributor
timestamp: October 23, 2022, 05:49:58 pm
content: Thank you for the reply. I don't think the RT9261A matches the pinout. I think the pinout I need matches the example. What confuses me is that there are so many chips that match this pinout. I am not sure how critical the part is if it meets the current and voltage requirements. Something like the MP1541 might work.https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP1541/document_id/4071Any comments?

author: R-1125F
author_rank: Regular Contributor
timestamp: October 30, 2022, 07:17:09 pm
content: I never could find out exactly what this part is so I took a chance and picked one that looked like to would work. I ended up using the Microchip MIC2287C in the SOT-23-5 package. It works fine. Brightness is good and all display functions are working.
Rigol DP821 not starting - Page 1
Forum section: electronics / repair

author: R-1125F
author_rank: Regular Contributor
timestamp: August 17, 2025, 06:34:37 pm
content: I picked up a dead Rigol DP821 power supply (similar to DP831). The fan spins and the front panel buttons light up and the screen remains blank. I have not worked on one of these before. The front panel is getting 5.2V, which seem right.Can the front panel be powered up detached of the main unit? I am hoping to show something on the display to make sure the controller is working.

author: bombcat
author_rank: Contributor
timestamp: August 18, 2025, 01:56:07 am
content: The front panel can be removed,be careful not to damage the FPC.I found some photos on the web.The DP800 all similar.

author: R-1125F
author_rank: Regular Contributor
timestamp: August 18, 2025, 02:26:36 am
content: Thank you. What I am trying to find out is if the front panel can be powered up independently of the rest of the power supply. I don't think it will do any damage to try.

author: bombcat
author_rank: Contributor
timestamp: August 18, 2025, 03:13:16 am
content: Yes, the front panel has independent power supply. You can try. (correct voltage)
Rigol DP832 - Channel 1 Analog Board - Schematic Fragments - Page 1
Forum section: electronics / repair

author: pedro48
author_rank: Contributor
timestamp: January 09, 2022, 09:19:26 pm
content: Hi folks,Attached is a start at mapping the DP832 Channel 1 Analog board, Please be aware this work though mostly DONE is a bit incomplete, and there are possibly errors, but I could not find anything that looked like a schematic, so I've had a crack here ... several contributors to this forum assisted greatly in observations and explanations of how things should work for the DP832.The attached KICAD schematic and PDF roughly follows the physical board in layout i.e. Left to Right, Top to Bottom. I have not made any attempt yet to ensure each trace is exactly aligned page to page, but they are all labelled so it should be readily traceable.Hope this helpscheers....

author: dwonga
author_rank: Newbie
timestamp: March 31, 2022, 07:06:36 pm
content: Thank you!Yesterday my DP832 second channel blew up (not CH2 or CH3 are working). An error appears when I turned it on "Analog board fails self test", and looking info about the issue, the device sais "Lower board fails". I think the information you made will be extremelly helpful. Thanks again.

author: RoGeorge
author_rank: Super Contributor
timestamp: March 31, 2022, 08:33:59 pm
content: Quote from: pedro48 on January 09, 2022, 09:19:26 pmThat's something I was curious about and didn't find anything yet, thank you very much!

author: Machlee
author_rank: Contributor
timestamp: March 29, 2023, 04:47:50 am
content: Good job.My DP832A does not turn off channel 1. Instead of turning it off, it is set to +33V.

author: Muttley Snickers
author_rank: Unknown
timestamp: March 29, 2023, 06:21:50 am
content: Quote from: Machlee on March 29, 2023, 04:47:50 amTheDP832 that pedro48 gave awayalso had a similar problem and unfortunately I haven't been able to give it the time or attention it probably deserves due to ongoing health concerns.Regardless of what is shown in the display have you actually measured the output with a meter?

author: Machlee
author_rank: Contributor
timestamp: March 31, 2023, 09:00:37 am
content: Also I found that this behavior in my appliance occurs not only when I turn off channel 1, but also when I reduce the voltage below 0.1 V. And the CV_REF signal remains proportional to the channel 1 output by a factor of about 1/15 even when a malfunction occurs. And no error messages. Looks like the reason is outside the analog part. Or may be analog processor has gone bad?