hybridfree/eevblog-posts huggingface dataset:
Newbie help pls measuring voltage on C836 on phillips pm3233 piwer supply  - Page 1
Forum section: electronics / repair

author: jimnoonan@sky.com
author_rank: Newbie
timestamp: June 16, 2021, 04:23:19 am
content: I feel very foolish asking this but I am confused. My pm3233 has 2 visible traces but no response to any x inputs at all. I have done visuals and set up adjustments to no avail. and am now looking at power supply measuring across the caps at top of the board as per manual. C836 is on the minus 12v rail. The cap is physically orientated to the opposite polarity of all the other power rail caps. so I measure with my dmm with positive lead to positive end of cap and I get plus 12v. I feel really stupid but am I right to assume that my dmm leads should correspond with the orientation of cap being measured in each case. If my approach is right the cap is inverted.....if my approach is wrong.....I could measure all the other caps in reverse and they would all be giving a negative voltage. Any guidance very much appreciatedThanksJim

author: Renate
author_rank: Super Contributor
timestamp: June 18, 2021, 05:59:30 pm
content: Sorry, you're going to have to link in a schematic.Not everybody knows what C386 is, but I'm sure people will try if you give a hint.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: June 18, 2021, 06:37:40 pm
content: If the cap is "on the -12V rail" that means the cap's positive terminal is connected to the 0V reference level ("ground") and the cap's negative terminal is connected to the -12V supply. Right so far?So if you just put your DMM across the cap, with the DMM's positive lead to the cap's positive terminal and the DMM's negative lead to the cap's negative terminal, you will read +12V, since the circuit's 0V reference level is 12 volts above the -12V rail. Right?So what seems to be the problem?
Newhaven IPS LCD Backlight Issue - Page 1
Forum section: electronics / repair

author: InsertUsernameHere
author_rank: Contributor
timestamp: January 10, 2022, 04:08:28 am
content: Hi guys,I have a few of these LCD's (NHD-7.0-HDMI-HR-RSXP-CTU) out in prototype systems and we have started having back light failures (2 in one week).I'm not 100% sure on the best way to try and trouble shoot this one as everything seems to be ok.The weird thing is that when I put my multimeter across D4 (in voltage mode) the backlight magically seems to come back to life, D4 seems to test ok as well.I'm not too sure if its something to do with the driver chip maybe?Any ideas how to test and trouble shoot this one?Cheers guys.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 10, 2022, 09:21:04 am
content: Is the control line properly driven it a high pull up, parts around the chip okay, well soldered, are they properly rated and having good values as given in the reference design ?? (havent seen the datasheet)Clean input voltage ?, is the backlight circuit on the good display is under 200 ma ?If you say your circuit work for a short time, is the driver Ic overheat ??Good connectors contacts, I had a similar problem with our 7" Sharp displays, it was based on 3x led group on a 24vdc backlight system, when we moved the backlight fpc connector, we could see some leds (group) turned off, it gave a strange effect on the screen bottomEDITOH ok i see the display specs and photos, it has eveything on its back, hdmi interface, supply input, drivers ic's etc ... nice oneIs your supply range is between 5 to 7 vdc at 1.3 amps ??Do you use the external pwn connector ??

author: InsertUsernameHere
author_rank: Contributor
timestamp: January 12, 2022, 12:48:17 am
content: Yeah the Power Supply is good, I also have tested with my bench power supply.I dont use the PWM so the display is just always on 100% brightness.The displays have been working for over 12 months now out in the field so I dont think its an overheating issue.Everything looks to be ok.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 12, 2022, 01:47:40 am
content: maybe drop the intensity by 5 - 10% by the pwm inputcould make it last longer ? since it wont be at 100% all time.
newish source for most lcds backlight repair, reparing a Fluke PM2812 - Page 1
Forum section: electronics / repair

author: ErwinsCat
author_rank: Regular Contributor
timestamp: November 04, 2020, 11:16:25 am
content: I recently scored a 2channel fluke PM2812 system power supply, I wanted to mod and hack the unit to use it as benchtop power supply. I had some minor issues which fixed, there is a small issue and I might post a new topic for help.this post is about fixing the LCD backlight. I tried to find a suitable ELbacklight for the unit but the only seller I found was in the UK and despite their wide range of sizes, the only option was to buy a long ribbon and cut it to the size and everybody considers is a bad idea because it damages the seal and causes the light die prematurely.I saw someone used an iPhone backlight for another project online and thought to give it a go an after 1 hour fiddling with it I have to report it worked beautifully, even better than what I expected.the only hiccup in the surgery happened when I tried to trim the backlight to correct size and cut the flex board and severed the backlight LED connection but fortunately there was enough conductive left on the last led to solder a tiny enamel wire on both sides of the LEDs (4 LEDs in series). for the powering LEDs, I wanted to use 7812 to bring the 24v to 12 as 4 LEDs in series worked perfectly on 12V and draining 10 ma. unfortunately couldn't find any 7812 in my stuff and didn't want to mess with switching converters either. anyways I figured the easiest way to power the LEDs was just a resistor in series and it powered the LEDs on 24V under 9 ma. I taped the existing 24V connector on the PSU board.anyways the moral of the story is you can use this backlights for almost everything as they are dirt cheap, low voltage / low power, very low profile and come in different sizes. I'm assuming the tablets using similar technology and if that's true you can find a match for almost any LCD size. and if you prefer coloured backlight you can use filter to change the white light.I didn't mean to create this post so I didn't take good photos before I cut the backlight but it is not hard to imaging cutting a flexible backlight. I'm planning to add a backlight to my Tektronix dmm916 multimeter and if I find a way to fix the voltage issue, I might take better photos and document the procedure.
NEC MultiSync PA272W - Page 1
Forum section: electronics / repair

author: Omicron
author_rank: Regular Contributor
timestamp: September 23, 2023, 11:52:52 am
content: Hi All,I'm trying to repair a NEC MultiSync PA272W professional monitor. It got hit with a power surge during a lightning storm. No other devices in the same office were damaged, so I think it just got hit with a surge that proved too much for an already aging component. The power supply is dead and one chip has blown its top. It's a 7 pin chip, I think a PWM controller. It's on the primary side of the PSU. I've attached some pictures. Could anyone help me identify this chip? The model number of the PSU board is HKM1102SL32-3A.Best Regards,Kurt

author: Swake
author_rank: Frequent Contributor
timestamp: September 25, 2023, 04:24:52 pm
content: Those 7 pin chips are fairly common.example: LNK304DNSearch for the datasheet and see if it is compatible. Several models, you might have to compare for best fit.

author: Omicron
author_rank: Regular Contributor
timestamp: October 03, 2023, 11:07:02 am
content: I replaced the unidentified chip with an onsemi NCP12400BBHAB0DR2G. Also replaced one MOSFET and a 10 ohm gate resistor. Monitor works again now
Nexiq Usb2 Repair Help - Page 1
Forum section: electronics / repair

author: koolaid2600
author_rank: Newbie
timestamp: January 29, 2022, 07:05:27 am
content: Hi y'all I have been searching for some help and repair info. For Nexiq Usb2 Interfaces for my shop. Cant find any info other then installation manual if any one can help I would greatly appreciate it. Thank you.
Nextion 7" display  - Page 1
Forum section: electronics / repair

author: Jpeeters19
author_rank: Newbie
timestamp: May 16, 2021, 05:59:34 am
content: Yesterday i damaged my nextion 7" hmi display while drilling. The drill shot out and completely destroyed capacitor c22. Does anyone happen to have a nextion enhanced 7 "display and would like to check the value of c22 please?
nextion NX3224T024_011 bricked - Page 1
Forum section: electronics / repair

author: technoturk
author_rank: Newbie
timestamp: January 29, 2023, 03:33:25 pm
content: Hello,my nextion NX3224T024_011 bricked last night during an update.last night i updated my nextion editor to v1.65.1 from a old version (early 2020)after finished update to v1.65.1 then i tryed to upload my project via serial port,and right after that it sayd that i have to update my nextion display to the new FirmWare version (cant remember wich Version it whas)so i clicked OK and the flash showed succesfully 100% (took 5min)but now i have a black screen and no sign of live via serial com porti found a legacy fix.tft file from a forum but that fixed nothing, looks like its only for nextions with a itead logo on pcb, mine has a nextion logo.is thare a dump file or something to flash it manualy ?what can i do now ?
NI GPIB-USB-HS repair attempt - Page 1
Forum section: electronics / repair

author: matthuszagh
author_rank: Frequent Contributor
timestamp: October 13, 2021, 04:44:22 am
content: This is a short post intended to document my so far unsuccessful attempt to repair a cheap Ebay NI GPIB-USB-HS adapter.The first failure symptom was that it started to stall during an HP 3048A calibration attempt. Then, when I unplugged it and plugged it back in it would no longer show up as normal in the NI MAX application. The device manager and the NI MAX app both presented it as "usb\vid_3923&pid_709b".The inside of the unit looks slightly different than some of the others I've seen posted online.In particular, there is no part number on the IC that is normally labelled as an NI part. Additionally the pictures I've seen show a conductive shielding paint on the inside of the case. This unit doesn't have that.A MAX604 chip regulates the 5V USB voltage to 3.3V for the USB controller (CY7C68013A), RAM (CY7C1399B), probably I2C EEPROM (24LC256) and possibly the NI IC as well, though I didn't check this. Probing the MAX604 showed 5V at the input and output. The next step was to determine if that failure caused any other devices to fail. So, I removed the MAX604, connected the USB cord (maybe some devices require the 5V) and powered the 3.3V rail from an external supply. No luck. The device now completely fails to enumerate. 3.3V current draw was about 40mA.At this point I could continue to troubleshoot, but considering the fairly low cost of these knockoff clones, it might not be worth it. Also, I'm concerned that the 5V on the 3.3V rail could have taken out multiple devices.I may just order another one of these, though I'd be interested to hear if anyone's had luck with other options (especially Ethernet-GPIB adapters). I'm not especially impressed with the durability of this unit considering the minimal use/wear it received. It also makes me nervous to connect it to more valued HP equipment.

author: syau
author_rank: Frequent Contributor
timestamp: March 30, 2022, 03:52:47 am
content: My unit failed in a similar matter and fixed by replacing the RAM CY7C1399B.The failure mode is a ! next to the usb device in window device manager.
NICE automatic gate controller and ants - Page 1
Forum section: electronics / repair

author: jtu
author_rank: Unknown
timestamp: April 15, 2018, 07:14:58 pm
content: My automatic gate stopped working after ~10 years of the service. I opened the controller, mains were present, but no signs of life. There was too much dirt kind of stuff present inside I decided to tear it down for cleaning anyway. There was no actual repair needed. The root cause was just ants trying to make a nest inside. My guess is that one of the anties made a small brown splash I cleaned off. After cleaning and changing the fuse it is working again. This was easy. Maybe should be published under teardown instead of repairAnts tried to make their nest, laid eggs mostly against / around the the high side of the power supply. Interesting choice.Strange that this nice NICE Italian device is actually open from the downside... Not just ants, any worm and even mice could get inside. And it is supposed for outdoors use by design, but it is just IP44.Few picsfor those with mostly visual perception.

author: Zucca
author_rank: Unknown
timestamp: April 15, 2018, 07:28:48 pm
content: In Italy ants go in the kitchen

author: jtu
author_rank: Unknown
timestamp: April 15, 2018, 09:04:51 pm
content: Quote from: zucca on April 15, 2018, 07:28:48 pm

author: Arek_R
author_rank: Regular Contributor
timestamp: April 15, 2018, 09:15:57 pm
content: If I would be doing this I would spray paint entire PCB in some dedicated lacquer.

author: jtu
author_rank: Unknown
timestamp: April 16, 2018, 07:34:01 am
content: Quote from: Arek_R on April 15, 2018, 09:15:57 pmThis is a good idea, thanks. I'll add it to my to-do-some-day list.

author: teresahuff
author_rank: Newbie
timestamp: November 30, 2021, 04:39:00 pm
content: Yes, this is a common problem that happens to those who don't protect their gate opener. I had one once that was really old, and it stopped working on the day. I couldn't get it out because it was full of rust. I tried using different tools to get it out, but I ended up making it worse. I had to contact  and have them get it out and repair it, and it has been working very nicely since. They said that the problem was caused by water entering inside the gate opener and making it full of rust. Since then, I have always put something on it to protect it while it's raining.Edited by Moderator to remove possible spam link.

author: shakalnokturn
author_rank: Super Contributor
timestamp: December 02, 2021, 12:28:03 am
content: Quote from: Arek_R on April 15, 2018, 09:15:57 pmI have an air con. PCB in for repair, it's mostly lacquered but there are some power components (in isolated packages) mounted to a large heatsink, a slug got in and earth leaked itself between a TO220 diode and the heatsink.You can't win against water and beasts unless you pot the electronics, then for some reason it becomes less reliable by itself and can't be repaired when fails...

author: fordem
author_rank: Regular Contributor
timestamp: December 02, 2021, 07:51:51 pm
content: Hermetically sealed boxes are readily available.
niceboy portable speaker ic identification - Page 1
Forum section: electronics / repair

author: malarkey
author_rank: Newbie
timestamp: February 16, 2025, 08:54:23 pm
content: Hi, I'm trying to repair my portable speaker, but I can't find anything about this BP1H730-6684 chip. There was corrosion around the chip and I think it is damaged because the voltage and the signal from the power buttons go into it

author: fzabkar
author_rank: Super Contributor
timestamp: February 17, 2025, 12:06:05 am
content: It looks like a custom IC.https://www.zh-jieli.com/product/https://www.zh-jieli.com/product/product.php?class2=112
Nicolet 3091 Oscilloscope Resources ? - Page 1
Forum section: electronics / repair

author: weirdaljr
author_rank: Contributor
timestamp: September 15, 2015, 03:34:51 am
content: Hello All,I recently aquired a older Nicolet 3091 Digital scope and I am having some fun trying to get it up and going, but I am having trouble finding any good resources online as far as a downloadable owners/operator manual, and/or service manual. I've done multiple searches, but only found spam links and junk. I know its a long shot, but anyone know where I might find one?Thanks in advance all, I appreciate any help I can get!

author: tec5c
author_rank: Frequent Contributor
timestamp: September 15, 2015, 10:53:25 am
content: There was a thread not too long ago about this exact query. The outcome was never posted, though perhaps you can PM the thread starter and see how he/she got on with finding a manual.Thread here:https://www.eevblog.com/forum/buysellwanted/wtd-(us)-service-manual-for-nicolet-3091-oscilloscope/Also, it seems there are copies of the service manual for sale on eBay etc.http://www.ebay.com/itm/Nicolet-Manual-3091-Digital-Oscilloscope-Service-Manual-w-Schematics-/301590023531

author: weirdaljr
author_rank: Contributor
timestamp: September 16, 2015, 12:48:20 pm
content: Thanks! I contacted him yesterday through here after your suggestion, maybe I will hear back there. Following the other thread suggestion I also reached out to Thermo Scientific and received a prompt response letting me now they sold Nicolet's Oscilloscope business "long ago" to "LDS Test and Measurement". Unfortunately my search on them shows they were purchased in 2008 by "Brüel & Kjær", so I am starting to think this route may be a wild goose chaseSadly I am starting to think eBay may be my only option.

author: Eprentice
author_rank: Newbie
timestamp: November 18, 2018, 07:08:36 pm
content: I hope you bought the service manual from eBay. I've been searching for it and this forum is the best lead so far. Please let me know if you do have the service manual (for the Nicolet 3091.)

author: eDan
author_rank: Newbie
timestamp: December 05, 2022, 06:53:28 pm
content: Hello all that are seeking information on the Nicolet 3091.My first engineering job was with Nicolet. The first instrument that I shared design responsibility was for the 3091.I recently bought one of these - more for a sense of nostalgia than anything else.I do not have the schematics - and would be interested in finding anyone that does have a copy.Please send me a note at <contact@eclektronix.com> if you want to chat about the 3091.My memory is not 100% after 45years or so, but I do recall some of the design aspects.Dan
Nikko QSR-4040 Receiver Distortion Repair - Page 1
Forum section: electronics / repair

author: Arty30
author_rank: Regular Contributor
timestamp: April 17, 2024, 09:43:46 pm
content: I'm starting a new thread since it's been quite a while and want to start from the top. In summary I received this receiver which has distortion on both front and rear left channels, coincidence?, I have since re-capped it in an attempt to resolve the issue as I have done in the past. this was unsuccessful though an there was still distortion. I did some more tests including testing the power amp separately from the rest of the powertrain. It appears only the power amps are the culprit. For this thread I am focusing on the rear left channel which exhibited popping at 'idle', possibly low volume, and bass distortion. distortion was only present at higher volumes or bass frequency. my next target was transistors, I had a pioneer that had it's issues solved this way. This unit has 2 C853, one C545, and one C945 as well as a pair of C1061 main amp transistors for each four channels. I replaced them with BD139, BD140, and 2SC1815 respectively. upon testing there is still distortion on the bass frequencies and/or at higher volumes, but it sounds more uniform if you will. I plugged in a function generator on the input and a scope on the output to view a sinewave input. what i found was that as I increased the volume on the unit, the top of the sinewave would be cut off, and by the time I reached full volume, it resembled more of a square wave. This leads me to believe I have made a bad choice in transistors or I need to adjust something somewhere. I will link a YT video I recorded of this setup first on the Left (bad) channel from low to high volume, then on the right (good) channel. they seem to exhibit similar behavior, but the left channel seems to saturate sooner. I am under the assumption that it should be a smooth sinewave all the time unless I am just oversaturating the amp with too much amplitude on the input. At this point I am beyond my knowledge and I am open to any tips, tricks, advice, etc, and would greatly appreciate it.YT video:https://youtu.be/IwG8PgkSc_UP.S I don't have a schematic for this unit, if anyone has one or can get a copy, I would be in your debt.P.P.S I'm also looking for a schematic for a Harman-Kardon sr-300b receiver.Thanks, Arty.
Nikkor Lens Silent Wave Motor (SWM) - Page 1
Forum section: electronics / repair

author: sdancer75
author_rank: Frequent Contributor
timestamp: April 22, 2020, 09:26:01 am
content: Hi,Is there any way to test -if it's working- on the bench the Nikon's (SWM) supersonic motors that are they used in the lens autofocus?What destroys them? The specific motor was almost new.https://www.nikonimgsupport.com/eu/BV_article?articleNo=000006503&configured=1&lang=en_GB
Nikon Coolpix P7000 SD card slot repair/replace - Page 1
Forum section: electronics / repair

author: Hogwild
author_rank: Regular Contributor
timestamp: September 15, 2021, 03:28:17 am
content: Hi everyone:I dropped my Coolpix P7000 on the ground. It was in a camera bag at the time,but apparently, that made no difference.One thing I've noticed since is that the camera doesn't recognize the memorycard. Should I assume that means the card reader is damaged, or could thatbe due to something else?Has anyone taken apart a P7000? How hard is it to replace the card reader?

author: amyk
author_rank: Super Contributor
timestamp: September 15, 2021, 03:44:03 am
content: Check for cracks in solder joints or PCB tracks.

author: Hogwild
author_rank: Regular Contributor
timestamp: September 15, 2021, 03:45:36 am
content: From dropping it? It only fell a couple of feet, and onto grass(I think, actually someone else dropped it, but I digress).Also, I'm not ready to take the camera apart yet. I'm waitingto order a new LCD screen, cause that was damaged in thefall too.

author: wilfred
author_rank: Super Contributor
timestamp: September 15, 2021, 05:01:37 am
content: If you do take it apart can you let me know where the internal battery is and how much disassembly is required to replace it? And what type of battery it is.If your internal battery hasn't been replaced then consider doing that while it is open. My P7000 doesn't remember the date-time settings anymore.

author: Hogwild
author_rank: Regular Contributor
timestamp: September 15, 2021, 05:05:41 am
content: Uh, well, uh...I'd be happy to, but I'll have no camerato take pictures. It's a catch-22 situation.PM me for the manual you are looking for. I will send itto you.

author: Hogwild
author_rank: Regular Contributor
timestamp: October 11, 2021, 11:04:24 pm
content: Wilfred:You do know about the teardown of the Coolpix P7000 on ifixit, right?https://www.ifixit.com/Teardown/Nikon+Coolpix+P7000+Teardown/62418There are also some other photos/articles there showing the internals of the P7100,which is very similar.
[SOLVED] Nintendo New 3DS XL | Where to find a spare IC (WiFi) - Page 1
Forum section: electronics / repair

author: w0nk1
author_rank: Contributor
timestamp: December 14, 2022, 04:46:47 pm
content: Hi guys,I just USB-C modded a Nintendo New 3DS XL from 2015. Unfortunately I damaged an IC which seems to be WiFi related. Can anyone tell me, where I can get a replacement part or at least which component this is?Maybe it is not an IC? Just guessing because of the arrow for the correct placement.Thank you very much in advance!CheersMarkus

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 14, 2022, 04:51:07 pm
content: The thing you circled is a 4MHz crystal.

author: w0nk1
author_rank: Contributor
timestamp: December 14, 2022, 05:09:07 pm
content: Quote from: PA0PBZ on December 14, 2022, 04:51:07 pmThis makes totally sense! Thank you very much for your fast reply!

author: gamalot
author_rank: Super Contributor
timestamp: December 14, 2022, 05:11:14 pm
content: It is a 4MHz crystal oscillator in 3225 package, highly suspected to be Kyocera brand
Nintendo switch doesn't power ON - Page 1
Forum section: electronics / repair

author: ABSTA
author_rank: Contributor
timestamp: June 09, 2020, 09:59:47 pm
content: Hey friendsMy Nintendo Switch is Down since few days,it can't turn onNo Led anyway the battery is Charging,i tested it with multimeter.I did some trace and i share with you results.for information , there is a trace of explosion behind battery connector side of the motherboard.

author: ABSTA
author_rank: Contributor
timestamp: June 09, 2020, 10:01:35 pm
content: another one

author: ABSTA
author_rank: Contributor
timestamp: June 09, 2020, 10:02:19 pm
content: and then

author: ABSTA
author_rank: Contributor
timestamp: June 10, 2020, 11:45:57 am
content: Up 🤕
Nintendo Switch Joy-Con - Not Working - Page 1
Forum section: electronics / repair

author: an231
author_rank: Newbie
timestamp: August 19, 2020, 09:02:38 am
content: Hello,I have a Joy-Con that doesn't work. A chip is missing as shown. Can anyone identify? Or indicate an equivalent component? I had to look at the other Joy-Con and I think I identified it but I can't find it.A friend also send a picture of is Joy-Con.Part Reference: D247BI appreciate the help.
nintendo Switch not turning on blackscreen charges at .46 - Page 1
Forum section: electronics / repair

author: psxpetey1
author_rank: Regular Contributor
timestamp: September 22, 2020, 04:38:46 pm
content: hey my dudes so I have a nintendo switch I am repair, guy who i got it from says it just shut off one day, inside its immaculate looks like its only been used a few times 9it was out of warranty) it had never been opened ( a far cry from most I've fixed hahah). It will slow charge at .46 but it wont switch to fast charging. Ive been checking for shorts around the usual suspect chips bq24193, m92t36 etc nothing yet.on the back I am getting the readings shown in the picture. no power on 5v? weird readings on 1.8v? has anyone ever come across this? Ive found in a few forums charging at .46 but the thread usually ends there. The p13 usb also gets the proper power does anyone have schematics with all the proper voltages, diode mode reading etc? A guy on tronics fix helped me out with a couple and and I got the diagram below from gbaforum.So any ideas?

author: psxpetey1
author_rank: Regular Contributor
timestamp: September 23, 2020, 02:40:31 pm
content: The person who owned this before me apparently hacked it and put it in auto rcm mode( meaning it boots cfw when a payload is injected(you need a computer to do this and an applet called tegra rcm) but it doesnt boot regular os and just shows black screen) when I connected it to the computer last night on the recommendation of a person in a another forum it showed up as in rcm mode. I then sent a payload and it works just fine lol. I checked if it was patched first of course. using this tool:https://ismyswitchpatched.com/. What a pain lol I spent a good couple days trouble shooting this. welp thats one down lol at least ill know the symptoms for the future.
Nintendo Switch SMD parts ID - Page 1
Forum section: electronics / repair

author: Elrod
author_rank: Contributor
timestamp: June 14, 2019, 04:23:44 pm
content: While working on a Nintendo Switch to replace the M92T36 power management IC, I managed to lose a couple of components. I will post a picture with them circled. Anyone have any idea what their value is?

author: fzabkar
author_rank: Super Contributor
timestamp: June 18, 2019, 05:24:12 am
content: I can't help, but here is a datasheet for a similar (?) IC:http://rohmfs.rohm.com/en/products/databook/datasheet/ic/interface/usb_pd/bm92t30mwv-e.pdfI suspect that yours is a BM92T36MWV.Check the pinout diagram/description and the application circuit.

author: Elrod
author_rank: Contributor
timestamp: June 18, 2019, 11:29:07 pm
content: Thanks. I figured out their values. The parts I thought I lost were stuck to the IC I had removed. 220K resistor and a .01uF cap.
NITP666SUC Bosch Induction cooktop  - Page 1
Forum section: electronics / repair

author: scottch
author_rank: Newbie
timestamp: November 20, 2021, 03:08:12 pm
content: NITP666SUC Bosch Induction cooktop - Bought new 2017 with unlimited 10 year warranty.This cooktop was purchased new but it was the display and i had read years ago that the cooling fans were loud in this model.Situation:Cooling fans have never come on from first day of use, so it makes me wonder if there is a way to program them to stay off? I ask because the warranty tape has not been cut and if i can turn them back on myself that would be great, but if not we did purchase a 10 yr unlimited warranty.
Nixie Tube Question: B5866 vs B5856. - Page 1
Forum section: electronics / repair

author: Paceguy
author_rank: Regular Contributor
timestamp: July 12, 2024, 12:33:00 pm
content: A question for those who know their Nixie tubes: Can a B5866 be used to replace a B5856? These are the simple +/- indicators used in Nixie tube voltmeters. From what I could find online, the only difference I can see is one in used for pulsed DC and the other isn't. It looks like the one for pulsed DC can be used to replace the non-pulsed DC, but the DC one cannot be used to replace the one made for a pulsed DC circuit.

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: July 12, 2024, 01:23:32 pm
content: Hi peaceguy,yeah, i guess you're right.Best regards

author: CaptDon
author_rank: Super Contributor
timestamp: July 13, 2024, 06:01:43 pm
content: The 'Long Life' series of Nixies are the only ones recommended for Mux/pulse duty. I think the long life versions have a bit more mercury content than the regular service versions. Cathode material migration from ion bombardment is the killer. The life of a Nixie is very dependent on average cathode current. You can download the catalogs including data and operating curves and guidelines for both Burroughs and National Nixies. I have observed three distinct Nixie glows, normal neon orange, neon orange with the blue mercury halo (long life) and the strange neon orange leaning a bit toward a pinkish tint. I am not sure what other gas causes the pinkish tint. I remember that some Nixies were doped with a radioactive isotope to insure ionization in pulse duty and dark environments. It is a well known fact that old Nixies and non-doped Nixies will either fail to ionize, or certain cathodes will fail to ionize in dark environments or in pulse duty. I have some 'lazy' Nixies in a rack mount device. When the unit is first energized the Nixies will flicker and carry on for about a minute and then settle down and work correctly. They are in a 1-of-6 multiplex scheme with about 9ma of peak current and 1.5ma of average current which is well within spec for the large long life tubes in the unit.
NMC27C64Q - Page 1
Forum section: electronics / repair

author: mpbrock
author_rank: Contributor
timestamp: February 20, 2020, 07:55:46 pm
content: HiI've got a piece of equipment which is Z80-powered (ancient!) and it has 2x NMC27C64Q's with the firmware in. As I'm unlikely to get the firmware ever again and I've had to repair this unit once due to a leaky RTC battery, i'm thinking i want to back up the contents of the NMC27C64Q for safe keeping.So I'll need an PROM burner - used an Xeltek Superpro about 10 years ago at work. I note the cheapy TL866's are kicking about, but i can't seem to find something that says yes it supports a NMC27C64Q. Can anyone confirm? If not, whats my best option - ebay for a second hand Xeltek? I'd rather have something thats half-decent as you never know when it will come in!Thanks in advanceMatt

author: free_electron
author_rank: Super Contributor
timestamp: February 20, 2020, 08:15:18 pm
content: 27c64 is a standard 2764 eprom , cmos version 12.5v programming voltage. happens to be made by national semiconductor.but there's many othe rcompatible devices out there.look for 27c64 in the supported device table. 12.5v programming voltage is the key.

author: JFJ
author_rank: Regular Contributor
timestamp: February 20, 2020, 08:27:39 pm
content: Quote from: mpbrock on February 20, 2020, 07:55:46 pmThe NMC27C64Q is in the supported device list for the TL866II programmer (in the Fairchild section):

author: mpbrock
author_rank: Contributor
timestamp: February 20, 2020, 08:39:58 pm
content: Thank you

author: 5065AGuru
author_rank: Frequent Contributor
timestamp: February 21, 2020, 04:30:22 am
content: Is there a reason why you don't want to save the data to a CD ROM? Easier and cheaper than an EPROM programmer.Cheers,Corby

author: mpbrock
author_rank: Contributor
timestamp: February 21, 2020, 07:51:20 am
content: Quote from: 5065AGuru on February 21, 2020, 04:30:22 amEh? :-)

author: johnkenyon
author_rank: Regular Contributor
timestamp: February 21, 2020, 11:24:13 am
content: Quote from: mpbrock on February 20, 2020, 07:55:46 pmAll you need is something to read the PROM, and then somewhere to archive it. Archiving to another EPROM is a waste of time, you won't be able to find it when you need it, and a binary/hex image can be stored anywhere (in a directory on an external drive with the precious digital photos is one free location).If I didn't have an EPROM programmer to hand, I would pull my BBC Micro Model B out of the loft, drop the device(s) into a spare sideways ROM socket, and then read the data out to the serial port in hex format to a PC.(And yes I have done this before back in the day - the BBC micro will ignore any ROMS which don't have the correct header details, but the devices are still readable)Then when you actually need a programmer, spend the money and buy whatever's current.jk

author: mpbrock
author_rank: Contributor
timestamp: March 06, 2020, 07:24:51 am
content: Thanks - i ended up getting a second hand TL866CS on eBay - hopefully it workswill get around to it eventually!Interesting @ BBC Micro - i'll have to have a look for interests sake!
No capacitance measurement on Meterman 35XP - Page 1
Forum section: electronics / repair

author: _rushin_or_draggin_
author_rank: Regular Contributor
timestamp: September 27, 2024, 06:19:48 am
content: Hey all,I was given a Meterman 35XP that works perfectly except for the capacitance reading. Whenever you set it to read capacitance it just flashes the screen about one time a second with every segment lit up on the LCD. I have opened the meter up and nothing obvious stuck out and with some slight probing I haven't found much of anything.I was wondering if anyone had any schematics for this meter or if they might have a good idea of where I should take a deeper look.Thanks!

author: J-R
author_rank: Super Contributor
timestamp: September 27, 2024, 07:19:44 am
content: Any chance you overlooked the fact that you need to move the test lead to the A/mA/uA jack?

author: _rushin_or_draggin_
author_rank: Regular Contributor
timestamp: September 28, 2024, 04:08:34 am
content: I didn’t think so but I went ahead and checked again and nope, still nothing. It’s almost like something is preventing it from going into capacitance mode. What’s weird if whenever the display flashes off, it seems to keep the nF and a few segments of a number lit up for just a fraction of a second before every segment turns back on. It’s a very weird fault

author: J-R
author_rank: Super Contributor
timestamp: September 28, 2024, 04:50:33 am
content: Since it shares the A/mA/uA jack with capacitance, is that fuse OK? Does it measure current correctly? "Input protection 2 A/1000 V fast blow ceramic fuse 6.3_32 mm on A input"Fresh batteries?Any change if you wiggle the selector while in capacitance mode?Check the DMM output with a scope? "Test frequency 1.3 Hz on 4 nF to 40 µF ranges, 0.7 Hz on 400 µF, 4 mF ranges"

author: _rushin_or_draggin_
author_rank: Regular Contributor
timestamp: September 29, 2024, 12:29:01 am
content: Went ahead and did all the checks. Batteries are new, wiggling doesn’t fix it, and fuse is good, but no output when switching the ranges. I do get a pulse when pressing the range button but no test signal. I noticed on the processor that 2 leads were bridged together. I removed this bridge and now I can press the range button and after it switches out of the nF range, it gives me a good screen and measures correct values, but it takes a very very long time.

author: J-R
author_rank: Super Contributor
timestamp: September 29, 2024, 02:31:26 am
content: The slowness is probably normal, due to the low test frequencies.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 29, 2024, 08:06:27 am
content: I also have a 35XP (bought second hand for EUR 30) and it's quite a nice meter.But it does look like yours is broken. When I have the dial in capacitance mode then the display just shows a steady 0.002nF with no leads at all. Yours should not be flashing.
No display of HP/Agilent 6812 AC power source - Page 1
Forum section: electronics / repair

author: heize0
author_rank: Contributor
timestamp: December 11, 2023, 01:00:00 am
content: I have an HP/Agilent 6812 AC power source.There is no display and only shift can sometimes be displayed if the shift key is pressed.I have seen the service manual. I checked the signals followed the instruction and found that there was no UART signal from the DSP. I tried to switch on and off many times and there was only one time the display segments were all lit up. More situations were either the shift could light up or the keyboard had no response.I tried to replace all 4 pcs of SRAM but it did not work.I suspect the program is corrupted. Did anyone back-up the firmware in EPROMs? I'd like to try it.My one is an original HP 6812A whose main oscillator is 54MHz.

author: heize0
author_rank: Contributor
timestamp: December 11, 2023, 06:59:24 am
content: Finaly it did work. I found two pins of the DSP were short after my re-soldering. Stuppy!Yet there are some errors related to the DAC12 1A & 1B. But it's better to have a display then I can debug it more directly.
No image on QLED Samsung TV QE55Q85RAT - Page 1
Forum section: electronics / repair

author: jbsers
author_rank: Newbie
timestamp: February 08, 2024, 10:16:20 am
content: Hello everyoneI have a QE55Q85RAT TV that no longer turns on - to be more precise, here are the diagnostic elements:- when I turn it on, the red LED flashes once, we hear a slight "zz" twice on the motherboard, then the LED flashes twice and this cycle repeats indefinitely- taking inspiration from certain forums, I put tape on 4 tracks of the ribbon which goes from the motherboard to the panel and then, the TV still does not show any image but the sound works and the TV responds to the remote control (I turned on the voice guide) - the TV being connected to the internet, I can hear the channels.Here are the tests I carried out with the TV running:- I tested the voltages on the power supply card, I noticed:350V for pin 5 which goes to the motherboard (CNM801 connector)46.7V for Vdrv (pins 3,5,7 and 9 of connector CNV901A)On the inverter card:2.85V for the BLU_ON/OFF pin of the cardI can find the 46.7v on pins 9,11,13 and 15 of the CNV901A connectorHaving read that the BLU-ON/OFF had to be at 5v to light the LEDs, I unplugged the Motherboard - Inverter cable and put 5v from an external power supply (batteries) on this pin - the panel did not turn on. yet not litI tested the 200 LEDs on the LED panel, all work.The diodes on the power supply board work, the 2 capacitors are not bulged (nor are the small ones)I lit the panel (front side) with a lamp but I don't see any movement through the transparency of the image.I fear that it is the panel which is broken, yet it is only 3 years old and has not suffered any shock.I admit that I have reached the end of the diagnostics - does anyone have any ideas on the subject?Thank you in advance for your help.Have a good day

author: natiz
author_rank: Newbie
timestamp: March 09, 2024, 09:30:20 pm
content: I have a similar issue, tried the ribbon thing - couldn't find a combination that works, sound-only, or dead. would be great to find a solution for it.
No image on ultra wide monitor  - Page 1
Forum section: electronics / repair

author: Rookie_Worker
author_rank: Newbie
timestamp: May 01, 2025, 10:07:48 pm
content: I have a Samsung Odyssey G9 49 Inch Monitor (model code:LC49G95TSSNXZA)Problem: Black screen/ No image. Powering on and even connects with PC, Just doesn't display anything.I have taken the thing apart like 10 times trying all kinds of stuff. It receives power from the PSU through the motherboard and TCON board. But drops from 20v to about 13v every 10 seconds when it cycles I am assuming. I basically have 3 questions that would really help me out with trying to figure this out.1. Is there any software that could be causing this within the monitor and how would i go about updating/checking it if there was with no display.2. Does this sound like a PSU problem like maybe stand by mode or something else in the Monitor is not letting it power up.3. Some people with this same problem, but different models have taken out a component that is supposed to shut it off, if it gets hot. That has made their monitors work again with no problem. But i can't find a way to find the same component on mine anywhere. how in the world do y'all find schematics and diagrams for this stuff?Any help would be greatly appreciated! It's pretty sad Samsung would put out this bad of a product for this high of a price tag with all these problems. This is my work computer and I really need it so any help really does help out a lot!

author: thm_w
author_rank: Super Contributor
timestamp: May 01, 2025, 10:13:35 pm
content: I guess its out of warranty? Supposedly it started off at 3 year but was reduced to 1 year, some debate here:https://www.reddit.com/r/ultrawidemasterrace/comments/10566zm/warranty_for_samsung_odyssey_g9_is_3_years_but/You can download the firmware on their website, but it may not be possible to install as the instructions talk about using the on screen menus to load it:https://www.samsung.com/us/support/answer/ANS10002051/

author: u666sa
author_rank: Frequent Contributor
timestamp: May 01, 2025, 11:58:03 pm
content: Black screen and no image are two different problems.Black screen = no back lightNo image & black screen = something elseDoes it show image in very very dark room or when you shine a flash light into the screen? Is this a back light problem or there is actually no image?

author: Rookie_Worker
author_rank: Newbie
timestamp: May 02, 2025, 12:56:22 am
content: No image and no backlight. I shined a light into it the other day and didn't see anything. I tested the power supply and get 20v, but it would drop to 13v every 10 seconds when it cycled. which made me think either something is making loop and not allow it to wake up. or there is something wrong with the hardware and it can't full wake up because of that. But this is not my area of expertise so I am learning as I go.

author: Rookie_Worker
author_rank: Newbie
timestamp: May 02, 2025, 12:57:24 am
content: It is out of warranty for my model as far as I know. I got one of them that had the 1-year warranty apparently.
NO OUTPUT VOLTAGE WITH RIGOL DP711 - Page 1
Forum section: electronics / repair

author: federico.petracca22
author_rank: Newbie
timestamp: October 13, 2025, 08:31:34 am
content: Dears,I'm very happy to be here in this forum.I have an instrument RIGOL DP711 with following problem:I have set 24 volt and I pushed the yellow fluo button but the instrument don't give tension on the positive and negative terminal.Fan works fine, instead on the display the tension is 0 volt.Can someone help me in order to understand what happens and what solution could fix this problem?Thanks!!!

author: bombcat
author_rank: Contributor
timestamp: October 15, 2025, 08:20:07 am
content: If you make sure you can，need open it。inside have a fuse. Check the fuse.
No Power - Tektronix TFP2A - Page 1
Forum section: electronics / repair

author: Mikemtsn
author_rank: Newbie
timestamp: April 26, 2019, 11:45:52 am
content: Greetings, I just came across a Tektronix TFP2A Fibermaster OTDR that has no power, I`m not tech savvy but I`d like to try and fix it, can someone help me out or point me in the right direction? Any help would be greatly appreciated, thanks.
no trace and toasty resistors mistery  - Page 1
Forum section: electronics / repair

author: pitpat
author_rank: Contributor
timestamp: May 17, 2020, 10:05:52 am
content: I got this hameg 103 scope to be rapired since it died on me while probing the cal. trace. It works in component tester mode but not in scope mode.After checking every components i found a bf199 transistor that was gone so i replaced it, changed the ac main to 240 ac that fixed the wrong values outgoing from the transf. and recapped all the board but still got no trace.The only thing suspicious is the big 2w 1k8 resistor that get proper hot with some magic smoke released if neglected.Scope schematicshttps://cdn.rohde-schwarz.com/hameg-archive/HM103_englisch.pdfSome photos of the scope fom an old treadhttps://www.eevblog.com/forum/testgear/hameg-hm103-problems-repair/what you guys think?Thanks to all

author: Gyro
author_rank: Super Contributor
timestamp: May 17, 2020, 10:56:19 am
content: You keep starting new threads about repairing a single piece of equipment (Hameg 103). If you keep starting different threads on the same subject, people will get fed up with cross posting the same information and just give up on you.https://www.eevblog.com/forum/beginners/oscilloscope-tranformer-extravaganza/https://www.eevblog.com/forum/beginners/bf199-equivalent/https://www.eevblog.com/forum/repair/help-with-resurrecting-an-analog-scope-(moved-from-another-section)/Use one of your existing threads and keep all the information together.

author: pitpat
author_rank: Contributor
timestamp: May 17, 2020, 11:06:26 am
content: You're right I'll try to keep all about this scope in one tread from now on.
No VCC to bios chip - Huawei Matebook d15 DAH98AMBAD0 REV:D HF Model H98A H898A - Page 1
Forum section: electronics / repair

author: Raygen
author_rank: Newbie
timestamp: October 01, 2024, 02:05:11 am
content: Hello, I received to repair this Huawei laptop (model in the title).The laptopwill charge the battery finethrought the USB C port, but it wont turn on. The charging led will blink fast and repeatedly when trying to turn it on.Here are some photos of the board:https://imgur.com/a/S96HHDW(the wires are for briging the power button, Idid notinject voltage)Upon visual inspection, a couple of ICs were blown. Along the 5V line leading to one of the USB A ports. They wasnt fully shorted but just a couple of ohms to ground.I replaced the blown IC on the board (the one circled in red, close up photo attached), and just disconnected the I/O board were the other blown IC was.This did not fixed the issue though.Main power lines are all up. 3.3, 5, and 12 volts present.Trying to search for any other short or blown ICs I've noticed a couple of things:Without the battery connected, the charging led will just stay stuck on. It won't blink fast and repeatedly like when battery is connected, if I try to turn it on. And yeah, the input power on the USB C will just fluctuate when trying to turn it on, but then fall back to nothing. It wont boot loop by itself. When battery is connected instead, input power for charging is steady and regular.One of the CPU coils (the one circled in purple) reads 1.2 ohms to ground, while all the others read 2.3 ohms to ground. I've no idea if it's normal or if the chipset could be fried.The Winbond flash bios chip has no VCC, even when trying to turn it on, it gets 3.3V for a split second but then goes away. I've followed the VCC pin to a small SOT-23 form factor smd (photo attached), which I gueees is a tranistor or mosfet? I could not find the datasheet through its markings. It has 3 pins: one pin goes to the vcc bios, one has 3.3V from the power line, and the third pin I guess is the control pin of the transistor. I've checked this third pin, and yup, it goes high for a fraction of a second when trying to turn on the laptop, and then goes back low.CPU doesn't feel warm.I do not have a thermal camera yet.Welp, I'm out of ideas, apart from the suspicion that the CPU might be toasted.Where does the third pin of that transistor / mosfet lead to? directly to the CPU? I could not find it.I've found schematics for this board from this thread:https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/schematic-requests-only/103079-dah98ambad0-rev-d-huawei-matebook-no-charge-need-schematic-or-boardview#post1851728But I don't thing they're the right schematics.For example: The pin out of the bios / flash chip does not correspond to the one in the schematics