hybridfree/eevblog-posts huggingface dataset:
Fluke 87 beeps like I've got probes in the wrong ports - Page 1
Forum section: electronics / repair

author: rszimm
author_rank: Newbie
timestamp: February 01, 2019, 03:47:19 pm
content: My original 87 got a light rain this morning (really just a misting). Everything seems to work on it, but I get the constant beeping that you get when you select a measurement mode that your probes are not setup for (i.e. Probes in current slots when selecting voltage or ohm reading), even when the probes are in the correct holes. Is there a way to fix this? Barring that, is there a way to turn this feature off?EDIT: I should mention that it only happens in the V/Ohm/Diode measurement modes. It doesn't happen on the inverse (i.e. if I select current mode and have probes in the current ports, I get no beeping)

author: ModemHead
author_rank: Frequent Contributor
timestamp: February 01, 2019, 06:54:21 pm
content: No worries, you probably just need to clean and dry the jacks. The lead alarm inputs are high impedance so it only takes a very tiny amount of current between the jack halves, to set off the alarm. Any sort of gunk inside the jacks makes the problem worse.Just in case there was water ingress inside the case, take it apart and lift out the circuit board assembly. Clean the inside of the jacks with isopropyl alcohol and some cotton buds. Finish with compressed air and clean dry cotton buds. Put the assembly in front of a fan or bathroom heater on low and allow it to dry thoroughly for an hour.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 01, 2019, 09:47:21 pm
content: For thoses i have at my job, a good dial contacts cleaning cleared the problem, it even beeped while powered off, thru the dialOh and a 83 did the same thing too, cleaned the pcb, all problems where gone, the 83 are kinda used very frequently
MOBO Diagnostic Card Comparison/Advice - Page 1
Forum section: electronics / repair

author: PKTKS
author_rank: Super Contributor
timestamp: February 01, 2019, 02:51:57 pm
content: Anyone already care about comparing latest cheapDiagnostic Analyzer Cards from CHINA ?A small query produces more than hundred results.Not counting companion PCI-e RISERS to have a bench GIGVideos, URIs, cheap hints... anything as a buyer guide will helpThankxPaul
Wine Cooler (post 031) - Page 1
Forum section: electronics / repair

author: billbyrd1945
author_rank: Regular Contributor
timestamp: February 01, 2019, 02:30:10 pm
content: Exaggerating about the number of posts. But from here on, I'll number them so that anyone intersted can follow along in order. It's not impossible that some other unqualified person might have a similar piece of equipment and might pick up a little something from my aimless attempts to find the problem.If you're a new reader of my saga, I'm attempting to repair a wine cooler with thermo-electric coolers (2) with a power supply for each, and a common break-out board. Every capacitor, every transistor, every resistor, every IC, has been replaced with new. The only things not replaced would be the three transformers. I've not been able to find matches for them. And replacing the boards entirely does not seem to be an option at any price. And even though it might not seem so to you guys with know-how, I am actually attempting to be systematic about the whole thing.In their current state, neither power supply will produce the 12.5v they are rated for. One will put out 11 volts, the other one ten. And in each case-- the voltages stated are without any load. Each load (cooler, fan, etc.) diminishes the output voltage so that it ultimately goes down to almost nothing. I know there's a clue there, but not for me.Today's question is in the form of measured voltages at discrete locations hoping that one of you might be tipped off as to what's going on. My measurements are taken from the two rectifier outputs and the collectors from each of the two transistors. I have attached pics as well as the schematic. Thanks for any help.
Following a HDMI signal path - Page 1
Forum section: electronics / repair

author: zzattack
author_rank: Regular Contributor
timestamp: January 31, 2019, 11:28:25 am
content: I have an AV receiver with quite a bunch of video capabilities, but unfortunately no HDMI output.The path is pretty clear to me. There's 2 muxes to support as many as 6 inputs, there's a 4k scaler that can be bypassed by putting the device in 'HDMI Through' mode and then there's 2 output transmitters.Since neither output provides any picture, the primary suspect is the common denominator 'HDMI Processor'.Rather than blindly replacing this chip I'd like to confirm whether there is indeed a problem here, but I'm not quite clear on how to do so. Are there signals I can probe to verify the bottom receiver is properly feeding an input into the processor (and so forth)? Can this be done with cheap equipment (I do have a simple scope, but certainly incapable of looking at HDMI TMDS pairs)?Code:______________| HDMI |___________ ___________ -----> | Transmitter | ----> HDMI OUT 1HDMI IN 1 --> | HDMI | | | / |_____________|HDMI IN 2 --> | Processor | ------> | 4k scaler | --o-----|HDMI IN 3 --> |___________| | |___________| | \ _______________^ \-------------------/ -----> | HDMI || | Transmitter | -----> HDMI OUT 2__________ |_____________|HDMI IN 4 --> | HDMI |HDMI IN 5 --> | Receiver |HDMI IN 6 --> |__________|

author: wraper
author_rank: Unknown
timestamp: January 31, 2019, 12:05:24 pm
content: It would be way more useful to write actual model and attach a good quality photo of PCB.

author: zzattack
author_rank: Regular Contributor
timestamp: January 31, 2019, 12:14:28 pm
content: I've omitted those on purpose, as I'm more interested in the general sense of how to approach such a digital video signal issue, regardless of the actual chips used. Right now I'm not quite sure where to start, what signals to probe and what to expect. Filling in the details for this particular PCB and the chips they used is not something I'd want to bother anybody else with.Now maybe there is no generic kind of approach and the perhaps this issue cannot be answered without knowing more about the PCB and chip datasheets. In that case I will certainly add those details.

author: wraper
author_rank: Unknown
timestamp: January 31, 2019, 01:40:39 pm
content: Quote from: zzattack on January 31, 2019, 12:14:28 pmYour omission omits too much. Something like this cannot be discussed in general as has many specifics. For example it could be something faulty preventing I2C bus connected to all of the chips in the signal path working properly. Faulty LDO or whatever.
JD785A false frequency signal repair - Page 1
Forum section: electronics / repair

author: HXG
author_rank: Newbie
timestamp: January 31, 2019, 11:11:45 am
content: First of all, let me explain that my English is very bad.I use Google Translate, so some statements may not look good, please forgive me.In the JD785A spectrum mode, there is no input signal, but the spectrum display has a false signal. Originally wanted to disassemble the machine from the hardware solution, did not succeed, and later heard that people can solve these false signal problems through self-calibration. So ask how the JD785A spectrum mode self-calibration process works. Thank you.

author: HXG
author_rank: Newbie
timestamp: January 31, 2019, 11:14:29 am
content: Other pictures

author: HXG
author_rank: Newbie
timestamp: January 31, 2019, 11:15:41 am
content: Other pictures
Anyone know a supplier/source of these connectors? - Page 1
Forum section: electronics / repair

author: peteb2
author_rank: Regular Contributor
timestamp: January 31, 2019, 07:42:54 am
content: They look like very high quality Lemo but they are in fact a 'knock-off' version very likely manufactured by a plant in China. I need to replace the 8-pin socket which has been damaged by the pins being inserted such both plug and socket are destroyed.The connectors are used on an LED illumination panel for video field production, the DMX controller unit joins the LED panel with this plug & socketI'm hoping someone may have seen an Aliexpress (etc) supplier offering these kinds of plug & socket. Any info appreciated....

author: giovannirat
author_rank: Regular Contributor
timestamp: January 31, 2019, 07:50:06 am
content: https://www.aliexpress.com/item/LEMO-Connector-FGG-0B-2-3-4-5-6-7-9-Pin-Male-Connector-0B-FGG/32836029840.html?spm=2114.search0104.3.217.408e3d8abdggSB&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_10547_319_317_10548_10696_453_10084_454_10083_433_10618_431_10304_10307_10820_10821_537_10302_536_10902_10059_10884_10887_321_322_10103,searchweb201603_51,ppcSwitch_0&algo_expid=dc630ae3-3b30-488f-a335-42f2207a5189-31&algo_pvid=dc630ae3-3b30-488f-a335-42f2207a5189&transAbTest=ae803_4
One of a kind fog machine, heater issue - Page 1
Forum section: electronics / repair

author: hmmmmm
author_rank: Newbie
timestamp: January 31, 2019, 12:47:24 am
content: Ive got a big fog machine laying around that im trying to fix. Its a bit special, because its a prototype that never went into production. Its looks like they used some quality components though, good pumps, Meanwell power supplies etc. It has both a fogger and hazer function, led lighting, big scroll fan, inline fluid sensor etc. Also, its appears to be brand new, internals look very clean ( i've had some other smaller foggers and they always have some rust or water spots on the inside when they are used for a while)Now here is the issue, the heater wont heat up. According to the LCD its heating, but nothing happens, not even after 30 minutes. Ive checked the following:-Followed the wires from the heater to the PCB. There is around 90V DC and 150VAC on the terminals on the PCB.-There is a heat fuse on top of the heater, that is not blow according to my multimeter.-When i check the 2 terminals on the heater itself, they are connected to each other, around 260 ohm. Ive read on the old interwebs that consumer grade heaters are usually around 100-200 Ohms. Seeing as this is more a pro grade unit, im thinking 260 might still be fine?-As soon as i connect the wires from the PCB to the terminal im not reading any voltage on the heater terminals.Im not sure on the voltages. Isnt equipment to either use DC or AC? Why am i getting both on the heater wires from the PCB? And if thats ok, why am i losing said voltage as soon as i connect the wires to the heater?Hope someone can help me out with this, i would really like to use this thing for a party in a couple of weeks.

author: David_AVD
author_rank: Super Contributor
timestamp: January 31, 2019, 01:25:54 am
content: 260 Ohms for a fogger's heater sounds very high. Assuming 240V, that's only around 0.9A and 220W of power.The "phantom" voltage on the heater drive (with heater disconnected) is just leakage through the TRIAC or snubber capacitor.It sounds like there's no real voltage being applied to the heater.
Fender Super Champ XD Needs New DSP Board - Page 1
Forum section: electronics / repair

author: gmeades
author_rank: Newbie
timestamp: January 30, 2019, 12:49:08 am
content: I've got a Fender Super Champ XD that I'm told needs a new board to get it working again.I believe it's the DSP Board (see attached pic).Fender just wrote back and said they no longer have the part...I've been looking at Amplifier Parts websites that come up on Google,but all they seem to carry are tolex, handles, tubes, etc.Does anyone know where I might be able to obtain a DSP board for a Super Champ XD from...?Thx...
CMU200: How to do reflow IC on DSP board - Page 1
Forum section: electronics / repair

author: Bicurico
author_rank: Super Contributor
timestamp: January 29, 2019, 07:25:05 pm
content: Hi,I have two broken DSP modules of the DIGITAL BOARD of CMU200/CRTU.This seems to be a common issue with these boards and looking at them, you see they are densly populated with FPGA's and such.There are no standard parts to break like electrolytic capacitors or similar, so my guess is that due to heat/ageing the lead-less solder used on the chips has ruptured.This was a common problem in that area with laptops and their GPU's.Repair consisted in reflowing or reballing. I had moderate success (and knowledge) back then and this is why I would like to ask:What are my chances to reflow this board by applying flux (lots of it) and heating it.I have a Aoyue hot air station, but I don't know which temperature and for how long I should do it.Any tips?I don't have much to loose, as the modules are broken for sure...Reballing is not an option as I lack the equipement and don't know anyone capable of doing it for me...Regards,Vitor
Help finding correct LDO - Page 1
Forum section: electronics / repair

author: firstcolle
author_rank: Regular Contributor
timestamp: February 02, 2019, 02:26:38 pm
content: Hi,I repairing a board without the schematic. the problem is an LDO but I can't identify it.what I know for sure:3.3V out (it's used to power up a reverb microprocessor that works at 3.3V)>12V inputthe package is like a SOT223 but smaller (body 4mm x 2mm SOT89??) and the pinout is:1- Vout2- gnd3- vintab gndI can read only BA mark on top, the rest is blown upcan someone help me?thanks

author: eb4fbz
author_rank: Regular Contributor
timestamp: February 02, 2019, 03:06:20 pm
content: There are a lot of linear regulators that could meet the specs. At 12V IN -> 3.3V OUT it doesn't have to be a LDO. For example L78L33ABUTR

author: wraper
author_rank: Unknown
timestamp: February 02, 2019, 03:45:57 pm
content: QuoteIf you had attached a photo, it's likely that other people would easily recognize it.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: February 03, 2019, 12:37:17 pm
content: Here is a list of SMD codes with BA:https://alltransistors.com/smd-search.php?search=BA
LG LCD repair - Page 1
Forum section: electronics / repair

author: evancharlton
author_rank: Newbie
timestamp: January 28, 2019, 08:58:24 pm
content: Hi everyone!We had a monitor at work that was damaged (in some unknown way; I think they dropped it?) by movers. Our IT department replaced it and the damaged one was headed for recycling, so I asked if I could have it. I figured that one way or another, I'll learn something new (or at least get to practice my SMD desoldering!)I've attached a picture of what it looks like when I plug it in. The image is trying to be there, but there are flickering horizontal stripes going on.I popped off the case and re-seated the ribbon cables -- no change. Where should I begin looking? Is this probably fatal (or at least impractical to fix)?Details:Panel: LM240WUAMonitor:FlexScan EV2455Thanks!

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 28, 2019, 09:30:57 pm
content: I'm having a little trouble telling from your photo but it actually looks as if the screen is cracked at the top of the red vertical column, If that's the case there is not much you can do other than replace the screen.

author: alienozi
author_rank: Newbie
timestamp: January 28, 2019, 09:32:04 pm
content: I might have several suggestions based on my previous work from different LCD monitorsCheck the ribbon cables and its' connectors maybe pins are damagedCheck the capacitorsmonitor driver board has lots of tiny connections maybe several of them are damaged to form a line

author: cdev
author_rank: Super Contributor
timestamp: January 28, 2019, 09:33:32 pm
content: (If you have the means of removing them) there are probably a lot of useful parts in it even if it does turn out the screen is cracked. But SMD parts require reworking equipment, a hot air gun - at the minimum- to remove them. Depending on your personal bench gear, it could be more trouble than its worth.To give an example of what kinds of parts might be found, LCD TVs that use LEDs for their backlighting often have a substantial number of unique large bright power LEDs in them.

author: wraper
author_rank: Unknown
timestamp: January 28, 2019, 09:58:04 pm
content: It's trash. LCD panel is certainly dead. Take out PCBs and dispose the rest.

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 28, 2019, 10:55:16 pm
content: Quote from: cdev on January 28, 2019, 09:33:32 pmAlthough it isn't gun shaped and nothing proves it is his own, it looks like a hot air rework station in that photo if you ask me.

author: cdev
author_rank: Super Contributor
timestamp: January 28, 2019, 11:24:54 pm
content: Indeed it does, I'm sorry, I really should have noticed that!
tektronics 475 sweep - Page 1
Forum section: electronics / repair

author: pa0nvd
author_rank: Newbie
timestamp: January 30, 2019, 05:16:52 pm
content: I am trying to repair a tek 475. The sweep seems without a capacitor connected across the integrator, there is sweep, but VERY high frequency. It depends upon the timebase switch, so the current source for the integrator works. The variable TB also works. The TB is that fast that it seems RF oscillation.I did verify that the TB capacitor bank marked A (between Q920 and Q922) indeed is connected and I can measure the capacitor bank of the TB switch at pin 6 and 12 of J6. I did measure all transistors and FETS and they seem all ok.When I pull the time base switch to engage the delayed time base, there is a microswitch upon the switch unit for the time base that actuates at the moment of pulling and when the TB switch is in a delayed position. . Than there is a normal sweep, but the variable TB doesn't work anymore. When I acuates only this micro switch, the scope works, good triggering etc., but the variable TB does not work.. The microswitch switches 5VDC on and off to the timing PCB. This microswitch is a simple on/off unit, the NO is not used. I can not find this microswitch in the schematic diagram or the description. When I actuates the microswitch, the voltage at the output goes to zero. Also pin 1 of J6 goes to zero and the TB works.Without knowing what the microswitch does and where it is in the diagram, I am puzzeledPlease some chime in to help me

author: pa0nvd
author_rank: Newbie
timestamp: January 30, 2019, 07:00:43 pm
content: Problem solvedQ1018 in the sweep generator was badFurther problems earlier solved were a leaking Q1316 in the HV/Zaxis part resulting in a -1kV at the CRT Cathode instead of -2.45 kV and a bad Q746 in the trigger generator.Now just calibrate and enjoying this marvelous scope
Philips DCM230 Entertainment System - Fixed - Page 1
Forum section: electronics / repair

author: davew_nz
author_rank: Newbie
timestamp: January 28, 2019, 06:32:28 am
content: Hi AllNow below is example of Duck Debugging, (https://en.wikipedia.org/wiki/Rubber_duck_debugging), the very act of writing this post to the forum gave me the answer, you will see the tone change as I typed, I thought it was worth sending anywayAs below;.......................I have a Philips DCM230 that is pushing 10 years old that has given up the ghost a few weeks ago. I can throw it away but instead I thought I would give repairing it a crack.The fault started as the display starting to wash out over a period of a few weeks before it got to the point where it would not power on.I have located the Service Manual (https://www.manualslib.com/manual/1184542/Philips-Dcm230.html).My first thought was that the issue relates to the supply voltage. The external PSU provides 14.97v DC as required.There are a couple of Caps for power smoothing (I think) so I pulled those and the 6600uf one was showing low so I ordered new ones and replaced them, no change.I tested the 7806 power regulator and the "Q3" P channel MOSFET (SPD18P06P) and both appear ok. The MOSFET is showing 14.8v on the Gate & Source so the trigger to turn off the is still powered up.Now I was running out of ideas, I have had this on my desk for weeks looking back at me.On the MCU there is a +5v and +7v line and plus an ECO & POWER-CTL lines. There doesn't appear to be power to the MCU so I traced back the MCU 5V line to Q11 voltage regulator and saw that was only getting 0.5v, the next component up the line was a 1/2watt resistor (R61) and this is where the penny dropped. R61 connected directly back to the Mosfet source, so it should have been showing 14.8v, it was showing 0.5v.There are no other components only a direct trace on the PCB between them, could that be the problem? The trace was covered in old glue that had turned a yukky brown colour and I remember seeing a YouTube video (Mr Carson's Lab) about this glue breaking down over time.I ran a wire from R61 directly back to the 14.8v source, connected it up and powered it on.... IT LIVES ! That was the problem.Thanks for providing a location where I can ask questions, sometimes the act of just thinking through the problem as you write it is all that is needed.RegardsDave
Screen for fluke 87 - Page 1
Forum section: electronics / repair

author: pcm81
author_rank: Regular Contributor
timestamp: January 28, 2019, 12:33:06 am
content: I have fluke 87 (original). Couple segments on LCD are burned out. I already did the carbon repair on the elastic connections successfully before. This time the actual segments are burned out.My question is:If i buy fluke 87V screen, will it work on original 87? I seem to be unable to find ebay listing for screen for original 87.Thanks

author: dacman
author_rank: Frequent Contributor
timestamp: January 28, 2019, 02:29:29 am
content: The part numbers are not the same. This one may work.https://www.ebay.com/itm/FLUKE-87-3-LCD-Display-Meter-Display-Fluke-LCD-Also-works-in-Fluke-87/264158203727?hash=item3d810e4f4f:g:KFQAAOSw~llcR7nk:rk:1:pf:0
GTX 980 Graphics Card MOSFET - Page 1
Forum section: electronics / repair

author: alicexyamasaki
author_rank: Newbie
timestamp: January 28, 2019, 01:48:35 am
content: Hi All,I have never attempted a graphics card repair before so I'm not sure really what to do. All I am sure of is that one of the power MOSFETS are broken (as shown in the picture) but I'm not sure as to what the primary cause was or how to go about finding it. I have searched on the internet for a schematic to try to identify different components but my luck has been very dry doing so. Although, I am pretty certain that the broken MOSFET is the 4C10N as it is in the array. What would be the best to go about for this repair and what could I do to try to identify the root cause of the initial problem?If it helps, it is a GTX 980 ACX 2.0, board id:n30233.Many thanks in advanced!

author: wraper
author_rank: Unknown
timestamp: January 28, 2019, 02:19:51 am
content: It may be different. Might be just this single mosfet dying by itself, it might also taken other mosfets with it. It might failed because of faulty controller, or opposite - damaged controller when failing. In best case scenario, replacing single mosfet will fix the thing.

author: Johnny10
author_rank: Frequent Contributor
timestamp: January 28, 2019, 03:45:35 am
content: What is oozing out of that chip?Looks like it was heated enough to melt solder on 6 pins.

author: mariush
author_rank: Super Contributor
timestamp: January 28, 2019, 06:34:16 am
content: Desolder the chip that looks blown up.Use multimeter to measure continuity between gate, drain and source pads of the other mosfets to determine if they're shorted or notMeasure continuity between input and ground of the vrm controller for a basic check to see if controller is shorted / dead.Measure resistances between mosfet gates and the vrm controller (or the phase doublers), see if there's anything shorted between those..If you're lucky, the video card used pairs of mosfets, in order to reduce heat on the mosfets, so if just that mosfet is dead, the video card may work and run (at least for testing purposes) with just one mosfet out of the pair, on that vrm phase.These videos are in russian, but maybe you can follow the tests he makes to see if other parts are faulty :mosfet dead on one phase of the vrm, took the controller with it :and a bit unrelated, but cool how he detects the memory chips are shotThe whole channel is worth bookmarking if you're into repairs

author: alicexyamasaki
author_rank: Newbie
timestamp: January 28, 2019, 09:51:14 am
content: Haha I hope it is the best case scenario. Although, the lights still turn on and the fans click a bit so they definitely still get power; leading me to think that maybe the controller is okay? I'm not sure!
Maplin mini-lab - Page 1
Forum section: electronics / repair

author: cowasaki
author_rank: Frequent Contributor
timestamp: January 27, 2019, 07:59:25 pm
content: In the mid or maybe late 80s I remember building the Maplin mini-lab. It was quite a challenge to build it with my rather poor soldering ability (I was self taught and it was terrible - it wasn't until college that I learnt how to actually solder correctly!). I completed it and used it for years then earlier today I found it on the shelf and decided to check it out. After checking it's earth I hooked it up and the variable voltage worked as did -12v and -5v. The 12v, 5v and all the 8 switchable outputs were out with a couple of broken switches as well.Taking it apart it became rather obvious that the original Maplin design was a bit crude, to say the least, and the mechanical design was terrible. I've had a look on the internet and there are a few issues people have had in the same areas. It's something I'm never likely to ever use again but nostalgia took over and I'm going to re-build itThe main board is a single sided board but the maker had to solder components to the board on the side that the component was located! This was NEVER going to help its longevity with voltage regs and two large 2200uF electrolytics sticking out of the board soldered on the top side and hovering a cm above the boardOh well, I'm still going to rebuild it, maybe with a slight mod as the the regs......It's a good job my soldering improved over the years.Has anybody else re-visited something they made years ago?

author: tggzzz
author_rank: Super Contributor
timestamp: January 27, 2019, 08:28:38 pm
content: Quote from: cowasaki on January 27, 2019, 07:59:25 pmYes. Although my first computer no longer exists, an earlier hack does. While it was the first one most people had seen, nowadays they are ubiquitous - so I recently updated it to be a little less ordinary.https://entertaininghacks.wordpress.com/2015/02/21/vintage-hacking-or-the-past-is-a-foreign-country-they-do-things-differently-there/https://entertaininghacks.wordpress.com/2015/02/21/a-40-year-old-hack-disinterred/https://entertaininghacks.wordpress.com/2015/02/23/vetinari-digital-clock/
FIX PS-40A ULTRASONIC CLEANER (10LT) - Page 1
Forum section: electronics / repair

author: phantom
author_rank: Contributor
timestamp: January 27, 2019, 09:18:58 am
content: hi to all i would like to fix my ultrasonic cleaner "PS-40A" dead during a cleaning process.i've found a short circuit on the logical board. the problem was this ic without namehow can i fix it?i have discovered only those pins
washing machine Siemens Siwamat XLP 1450 ( 2006 ) - Page 1
Forum section: electronics / repair

author: fonograph
author_rank: Frequent Contributor
timestamp: January 28, 2019, 10:40:07 am
content: My washing machine broke. The electronic module is slightly burned around transformer and on other side of the board in same place as the transformer. There was one big electrolytic capacitor 3mm away from the transformer but I ripped it out.Both capacitors showed no signs of buldging but the one near transformer was slighlty melted and it made tiny melted plastic bridge to the transformer. The transformer is covered in fine sticky black powder, the same black powder is on the two SMDs on the other side of the board where its burned too.The washing machine started giving me error F01 which means the machine thinks the lid is open when in fact its closed. Repair man came, tried to out new switch but it didnt help and after he left I opened it and taken the electronic module out. Please, if anybody has that module, PM me, I would like to buy it.

author: fzabkar
author_rank: Super Contributor
timestamp: January 28, 2019, 09:11:16 pm
content: The "burn" marks look like dust that has been attracted to the PCB by the high voltage in that area. It will probably clean up OK with a toothbrush and isopropyl alcohol.I would use a multimeter to trace the switch contacts back to the PCB. The problem may be as simple as a bad contact in the harness, in which case a new board would be a waste of money.
Vizio M421VT LED faulty! help - Page 1
Forum section: electronics / repair

author: silva1955
author_rank: Newbie
timestamp: April 18, 2016, 10:19:46 pm
content: Hi guys; i have this Vizio M421VT that has this synthoms see video, is this a A board issue or a bad panel!.https://youtu.be/YiSs0lPw6RY

author: Maverick923
author_rank: Newbie
timestamp: January 26, 2019, 11:27:11 pm
content: Hello,Just wondering if you ever got that resolved?
NGMO1 - unregulated > 10V - Page 1
Forum section: electronics / repair

author: orion242
author_rank: Unknown
timestamp: January 27, 2019, 09:27:34 pm
content: Tearing into my R&S NGMO1. Works fine up to 10V output even under load. Set the output to 10.1 and it falls to ~7v. The fan bearing is gone as well. No error on the display, reads correct voltage / current. Not in OVP or OCP. All the power rail LEDs on the main & analog boards are lit. Seems to have all the power rails to the analog board.Initial pic/notes on the analog board here.https://www.eevblog.com/forum/testgear/ngmo1-0-15v-0-2-5a-power-supply-teardown-(rohde-schwarz)/msg2154727/#msg2154727Thanks to those that posted the service manual here. Block diagram is there at least.https://www.eevblog.com/forum/testgear/calibration-procedure-service-manual-for-rs-ngmo2/msg988839/#msg988839I'll post more photos with comments and readings as I work through it.

author: orion242
author_rank: Unknown
timestamp: January 28, 2019, 01:32:58 am
content: Seems to be an issue to set the voltage. The LT1166 is getting a ~7v to pin 2 when the supply is set for 10.1v. Below that pin 2 & 3 match. Light blue is where pin 2 of the LT1166 seems to go. Note the test pad. Voltage there = output voltage, lest in this unit. Green is the main gate drive. Note without the heatsink in place, the main mosfets get hot quick and require attention.

author: orion242
author_rank: Unknown
timestamp: January 30, 2019, 01:20:52 am
content: Poked around some more.The LTC1650 seems to be the DAC in charge of setting the voltage. Test pad right next to it (labeled V Set) measures ~0.146v per volt set on the screen. Tested this @ 15, 10, 5, 2.5 & 1 volt, lined up nicely. Assuming its fine up to that point the fault has to be in the sea of op amps between there and the AD825s that lead up to the LT1166. Spent some time looking into the other test pads and trying to figure out what they correlate with while I'm tracing out the whole mess. Took a bunch of measurements at various settings around the DG409, test pad near the top (orange line) seems to be a fixed 2.440v. Pin 11 on the DG409 I suspect has to do current measurement in to ADC.Guess its either follow from the LT1166 up or the V set pad down.

author: orion242
author_rank: Unknown
timestamp: January 30, 2019, 02:06:47 am
content: DAC08Trying to wrap my head around this part. Am I correct to assume this is a current based DAC where the digital end is setting a multiplier that's applied analog reference current?What's the most likely purpose? Setting the output current limit I assume.
need help w/ wine cooler component ID - Page 1
Forum section: electronics / repair

author: billbyrd1945
author_rank: Regular Contributor
timestamp: January 26, 2019, 05:22:36 pm
content: I have two diodes that I believe to be zeners. The schematic uses that symbol but gives no value. One of them is marked C11 ST while the other one is C7V5 ST. I want to replace them both but would prefer something more than a guess if possible. Testing the C11 with a bench power supply, I get about 11.5volts, the C7V5 measures about 7.5volts. I haven't found listings for those exact part numbers. There will always be accompanying numbers or letters that, I assume, affect their value. I've tried looking at various datasheets, but I'm not sure what data confirms whether the component referred to is what I need. Unfortunately, all I know about the boards is that they ultimately output 8volts and 12.5 volts and they receive input from thermistors attached to the cooing units. Any help would be appreciated.

author: soldar
author_rank: Super Contributor
timestamp: January 26, 2019, 05:37:54 pm
content: I have an unexplainable hunch that C11 is an 11 volt zener and C7V5 is a 7.5 volt zener.https://uk.farnell.com/nexperia/bzx79-c11/diode-zener-11v-500mw/dp/1097214https://www.nexperia.com/products/diodes/zener-diodes/BZX79-C7V5.html

author: DaJMasta
author_rank: Super Contributor
timestamp: January 26, 2019, 08:06:49 pm
content: So is there something wrong with it? Sounds like you know the parts and they're reading the correct value.... so what's the fault?Sounds like the outputs are about a diode drop more than the zeners, which could be easily accomplished in a few ways with the zeners configured as shunt regulators, maybe biasing an output power transistor, but it sounds to me like they're working.

author: billbyrd1945
author_rank: Regular Contributor
timestamp: January 26, 2019, 10:57:15 pm
content: "Is there something wrong with them?"Leads damaged when removed for testing.

author: fzabkar
author_rank: Super Contributor
timestamp: January 26, 2019, 11:11:28 pm
content: You need to ensure that the wattage of your replacements is fit for purpose. You can do that by calculating the diode current from the circuit components in the vicinity.
HP 5246L Counter Troubleshooting/Repair  - Page 1
Forum section: electronics / repair

author: valley001
author_rank: Frequent Contributor
timestamp: January 25, 2019, 08:49:15 pm
content: Hello all,Next up is an HP 5246L counter. I have been playing around with it and and noticed that, when connected to my HP 650A (behemoth) signal generator, I get very accurate readings on the 1ms, .1ms, 10us, 1us, and .1us settings but 10ms, .1s. 1s it is counting high, double or more the indicated frequency from my scope.I do have a service manual on the way. The operating manual has you adjust the time base by externally triggering a scope to 100Khz (if I recall), but I do not have the ability to externally trigger my scope currently. If the readings are accurate on the shorter time base settings this would mean the internal time is good right?When I use the check mode it is also inaccurate until I get into the Mhz range, but its not too far out reading 9989Khz or so out of 10,000Khz.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 25, 2019, 09:14:33 pm
content: Maybe some kind of input divider stage / prescaler problemsIf you have the service manual try to follow the signal path you should end with the signal going into a gate, the gate will receive the 1sec 0.1 sec .... timings to let it thru the counter section.

author: jfphp
author_rank: Regular Contributor
timestamp: January 26, 2019, 11:06:31 am
content: It is probably the decimal counter, the last big board on the right of the displays boards (view from top) near the plug in slot : common failure on the 5246, 5L/M and 48L/M. A replacement board with ICs was very early the answer from HP.

author: valley001
author_rank: Frequent Contributor
timestamp: January 26, 2019, 04:27:55 pm
content: Quote from: jfphp on January 26, 2019, 11:06:31 amThanks for that information. I had a look at the one in my unit and it is all discreet components. Ill start there when the manual arrives.
Vizio M421VTT No Audio Issue - Page 1
Forum section: electronics / repair

author: Maverick923
author_rank: Newbie
timestamp: January 26, 2019, 02:26:44 am
content: Hi,I have a Vizio M421VT after much troubleshooting, I believe there audio on the mainboard to be faulty since there is no audio.I have tried to power cycle, complete reset, checked mute, checked tv audio is set to on, connected audio out, and Bluetooth.I hear something for a sec when flipping through channels with audio out connected to a small speaker. It sounds a lot like when flipping through radio stations very quickly.I change channels and when I stop I hear something for a fraction of a second on the little speaker.I have been trying to find a service manual for this tv, but I haven't had the luck to find any of the information I need.I would not know where to begin trouble should anything audio on the component level.Some help would greatly be appreciated.

author: Maverick923
author_rank: Newbie
timestamp: January 26, 2019, 08:33:10 am
content: Some help please. Perhaps a point in the right direction?
Toshiba WT8-A battery externaly charged but still won't turn on? - Page 1
Forum section: electronics / repair

author: torini
author_rank: Newbie
timestamp: January 25, 2019, 08:04:08 am
content: I got this windows tablet for cheap, the seller said the battery reads 0v, but of course he was measuring the output of the protection board and not the battery itself. The li-po cells had 2v each, I hooked up an external charger directly to the cells (which are connected in parallel) and charged it to +4v, after this the protection circuit was reading 4v on the output aswell, but the tablet still won't turn on.The battery has 3 red 3 black, 1 green, yellow, white, and blue wire. So it's not your usual 2 wire plug and play battery. Could it be that the protection board declared that the battery is bad and it won't power the tablet anymore? Also could someone explain what are those wires for, I know red,black for power and yellow or white is for temperature, but what are the rest?

author: HpMad
author_rank: Newbie
timestamp: January 25, 2019, 11:21:53 pm
content: I am actually reading your post on a tablet of the same make and model.If battery is fully charge and keeps the charge, then check if caps or diodes are short around the battery connector those tablets needs to be press around 2 seconds the power button in order to turn it on.
I dont know how to drive this motor (NIDEC motor) - Page 1
Forum section: electronics / repair

author: 44samul
author_rank: Newbie
timestamp: January 25, 2019, 04:14:36 am
content: hello people,I have a IG-A40E-W sharp plasmacluster hd ion generator air purification device.the ion generators have failed in it, and now it won't do anything,I have taken it apart with the intention of using it with the fan only and getting rid of the ion generator part of it.I basically gutted everything, the only part I want to keep is the fan blower and air filter.while looking at the motor, I couldn't find any information about it on google, and it requires 168 volts dc (rectified 120vac) plus an additional three wires (I don't know what the other three do),I would like to build a circuit to run it without using the mainboard, (since the mainboard does nothing now that the ion generators are dead).I am including a picture of the motor, it would be great if anyone has any info about this type of motor.20190124_220848

author: Armadillo
author_rank: Super Contributor
timestamp: January 25, 2019, 05:40:03 am
content: Hi;168vdc is lethal voltage, you know right? Please careful there.Normally the color code like this;Red = Vm = 168VDCBlack = GndWhite = VCC = 14VDCBlue = Pulse Gen Output = Don't careYellow = Control Speed Input = 0 to 5vDCProof of Concept for Safety Reason;Red = Vm = 24VDCBlack = GndWhite = VCC = 12VDCBlue = Pulse Gen Output = Don't careYellow = Control Speed Input = 0 to 5vDC

author: fzabkar
author_rank: Super Contributor
timestamp: January 25, 2019, 09:56:52 pm
content: There appears to be a similar motor (CMOT-A009KKEZ) in this Sharp air purifier model (FU-40SE-J):http://www.jordansmanuals.com/ServiceManuals/Sharp/AIR%20PURIFYER/FU-40SE-J/FU-40SE-J%20Service%20Manual.pdfSee page 19 of the service manual. Note that the FU-40SE-J is a 240VAC model.
Rigol DS1054 Trigger problem (sometimes it wont trig random)? - Page 1
Forum section: electronics / repair

author: fl
author_rank: Newbie
timestamp: January 25, 2019, 10:30:46 am
content: Hi(If wrong posting sorry, please move it)Problem is the trigger system on my DS1054, sometimes it wont trig random?Problem is when signal is small compared to the scale setting.Can be a 5v signal, with scale set to show a small signal, ex set scale to 5v no trig, when change to 2v it trig.Off cause i set the trigger level to trig the signal...I have other scope and no problem on them.Suggestion?
SOFT STARTER REPAIR - Page 1
Forum section: electronics / repair

author: biosautom
author_rank: Newbie
timestamp: January 27, 2019, 12:37:51 am
content: Dear colleagues. I do power electronics repair. I`m lloking for Siemens Soft starter schematics, internal electroic circuits. Does enyone know a place to find them? thnak you very much. Guillermo
CMM1200 CHANGER  HT70151 PINOUT - Page 1
Forum section: electronics / repair

author: laoadam
author_rank: Newbie
timestamp: January 24, 2019, 02:08:46 am
content: I have a CMM1200 mower came with a HT70151 changer, that has 3 output pins, any one know the pinout? Can I just use the positive and genitive pins to do the change?ThanksAdam

author: coromonadalix
author_rank: Super Contributor
timestamp: January 24, 2019, 02:56:56 am
content: should be this photo
Alternative part? LG 6202VDT002S CRYSTAL - Page 1
Forum section: electronics / repair

author: ElectroWonder
author_rank: Newbie
timestamp: January 23, 2019, 03:30:15 am
content: HelloQuick question: I have an LG monitor with a faulty crystal. The crystal is not currently available from LG, with no firm ETA for availability.I am wondering if any one would know of a suitable alternative?The LG part number is 6202VDT002SCRYSTAL.Thanks in advance!

author: Armadillo
author_rank: Super Contributor
timestamp: January 23, 2019, 03:43:07 am
content: Is it the type with the 4 pins?2 of the pins are connected to Gnd1 pin to Xtal in1 pin to Xtal out?Because you don't even provide photo of package? how to advice you?But I think it's a 25Mhz crystal, most likely used by them in their 34UC.

author: nsrmagazin
author_rank: Regular Contributor
timestamp: January 23, 2019, 09:48:48 am
content: Try to see them before the page gives the redirect dialog. I have not seen what is on the other page.https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjZ2dLcz4PgAhUFZ1AKHWWvDb4QFjAAegQIABAB&url=https%3A%2F%2Fwww.hkinventory.com%2Fp%2Fd%2F6202TST001P.htm&usg=AOvVaw1qaCvoKkp_nLafj94dlLiS]https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjZ2dLcz4PgAhUFZ1AKHWWvDb4QFjAAegQIABAB&url=https%3A%2F%2Fwww.hkinventory.com%2Fp%2Fd%2F6202TST001P.htm&usg=AOvVaw1qaCvoKkp_nLafj94dlLiS

author: ElectroWonder
author_rank: Newbie
timestamp: January 23, 2019, 05:51:32 pm
content: Sorry, i dont have physical access to the part, to provide a pic. It came from a 31MU97-B monitor. Ill see if I can get a pic of it.

author: Armadillo
author_rank: Super Contributor
timestamp: January 23, 2019, 06:18:55 pm
content: There are 2 crystals there. X200 and X300. Both are 12MHz crystal.Who tell you crystal spoilt and part number?You sure its crystal spoilt?[Edit: Attached suggested part, you need to confirm thru-hole type or smd version]
Repairing a vestax mixer and struggling to find "Miyama MS-610F Toggle switches" - Page 1
Forum section: electronics / repair

author: Deviant
author_rank: Newbie
timestamp: January 20, 2019, 08:12:05 pm
content: Does anybody know of any retailers/wholesalers that stock "Miyama MS-610F Toggle switches" or will sell small volume orders? or perhaps know part numbers of alternative replacements, im at a loss for ideas. Not sure if this is the right place to post as im new to the forum so feel free to berate me and point me to the right place if notMany Thanks, Tom

author: KermitTheFrogg
author_rank: Contributor
timestamp: January 20, 2019, 08:44:35 pm
content: Welcome!You can probably find similar switch in your local electronic's store. ( just look on the specification ! )

author: Deviant
author_rank: Newbie
timestamp: January 20, 2019, 09:10:10 pm
content: Thanks, I have looked at many data sheets today to try and find the same size from a different manufacturer and unfortunately all our local shops have closed downalso a very lengthy internet search was not fruitful. I am yet to find a similar size as its quite an obscure small version. I think it is possible to buy a vestax replacement but these are upwards of £ 25 for 1 small toggle switch if you can find them and being from yorkshire that insults me to the coreI was just trying to explore my options really. I have contacted Miyama directly to ask about their distributors and have also contacted a few distributors on the off chance they have some but not heard back yet. Iv been a keen EEV viewer for a while and thought it couldn't hurt to ask here too on the offchance that someone knew something i didn't with regards to this. No worries if not. Cheers

author: Deviant
author_rank: Newbie
timestamp: January 20, 2019, 09:15:34 pm
content: the data sheet for the part i require is herehttp://www.miyama.co.jp/pdf/MS-610.pdf

author: Deviant
author_rank: Newbie
timestamp: January 22, 2019, 08:44:57 pm
content: Well seeing as its only for me I think i will just bodge a different one in and bypass this useless pcb they attached it to, so over engineered. Love the high quality Japanese stuff but do i really need a DPDT switch soldered to a mini pcb with extra tracks that go nowhere just to do simple on-off
Dell C1760nw printer fixed - Page 1
Forum section: electronics / repair

author: james_s
author_rank: Super Contributor
timestamp: January 21, 2019, 06:05:01 pm
content: I was given this printer recently, a nice little color LED page printer that prints exceptionally nice output despite having been inexpensive. It worked except printing a full page caused the edges to not fuse properly making a gummed up mess. I thought the fuser sleeve was damaged but after ignoring the "don't take this apart" graphic and completely disassembling the fuser it turned out to use a conventional lamp heated roller which was in good shape. The sleeve was on the pressure roller and after scraping off the melted toner it turned out to be fine. Closely inspecting things I noticed that the two thermistors that monitor the roller temperature were both coated in blobs of melted toner so I carefully scraped those clean. I reassembled the fuser and put it back in the printer and was pleased to find that it now works perfectly. I can print a full page color photo and the entire sheet is fused flawlessly from edge to edge, I can no longer rub the toner off with my finger.I noticed the fuser for this popular and recently discontinued printer is out of stock everywhere so I suspect this is a fairly common problem. I bet tens of thousands of these printers have ended up in landfills due to a little gunk built up on a temperature sensor.

author: Gyro
author_rank: Super Contributor
timestamp: January 21, 2019, 08:18:30 pm
content: Worth knowing, thanks. I've got one too, nice printer and cheap toner availability.

author: GreyWoolfe
author_rank: Unknown
timestamp: January 22, 2019, 03:47:45 am
content: I saw that years ago on a Dell multifunction device. I friend was using it for her business. She bought a new printer and gave it to me to see if I could salvage it. On this one, the fuser flat failed. As you found out, there are basically no parts available for them. I would never buy/own/accept for free a Dell printer. I simply can't be bothered.

author: james_s
author_rank: Super Contributor
timestamp: January 22, 2019, 06:36:52 am
content: Well it was free, it was easy to fix, it does a superb job of printing, and consumables are cheap, no complaints here. It has about 7700 pages on it and was used as the main printer in a business for about 6 years. Yes it sucks no parts are available but these low cost printers are all that way, they're designed as light duty consumer devices.I've recycled higher end printers that were designed to be serviceable, parts were available but a full set of consumables costs more than a whole new printer so it hardly matters. I'm not about to pay $200 for a drum for a printer I couldn't sell for $100 when a color Laserjet office printer is only ~$300 brand new.