hybridfree/eevblog-posts huggingface dataset:
Hoover CH30000 Portapower thermal fuse replacement - Page 1
Forum section: electronics / repair

author: Paceguy
author_rank: Regular Contributor
timestamp: February 23, 2025, 06:51:49 pm
content: Hi, I looked up the service/owers manual and the thermal fuse is not listed. Can someone tell me the valus of the fuse? It it safe to rum it by jumping the fuse? Thanks in advance.

author: wasedadoc
author_rank: Super Contributor
timestamp: February 23, 2025, 09:41:20 pm
content: Any markings on the fuse?The fuse is there for safety. Why has it blown?
Hoover HPI430BLA/1 induction hob repair - Page 1
Forum section: electronics / repair

author: chema.rb
author_rank: Contributor
timestamp: March 10, 2021, 02:29:57 pm
content: Hi!Half of my Hoover induction hob is not working. One of the control boards seems to be the problem:R3 looks cracked and open circuit. Might it be that simple?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 10, 2021, 02:49:50 pm
content: Yeah, seems suspicious. Ohm it out, and everything after it. Why did it fail? Perhaps its load failed shorted -- I would hazard a guess, the axial diodes nearby are rectifiers for the nearby small HV electrolytic, and the DIP is a TinySwitch or something like that, and the E-core part is a flyback transformer; and this is all for LV control supply. Of those, the regulator (the DIP) would be the most likely culprit?Tim

author: perieanuo
author_rank: Frequent Contributor
timestamp: March 10, 2021, 03:00:13 pm
content: R3 is series limiting resistor for some voltage filtered with EC8 which in his turn makes another voltages with the transformer near him MD-EE19B, some smps I guessso yes, no R3, no 5V and 18V voltages marked on bottom sideresolder well all current paths, like D3 and so on

author: chema.rb
author_rank: Contributor
timestamp: March 10, 2021, 03:36:27 pm
content: Yes, is an SMPS, the DIP next to it is an ST Viper12A. Can't find any obvious short, I will replace the resistor (is a wire wound one) and see if it comes back to life.

author: perieanuo
author_rank: Frequent Contributor
timestamp: March 11, 2021, 06:30:56 am
content: check also for short the EC8 rails and around that viper, the resistor died of old age, bad design (my favourite) or short between those rails

author: chema.rb
author_rank: Contributor
timestamp: March 11, 2021, 03:20:58 pm
content: Thanks,Gave it a go with a 2W resistor, and it blew straightaway. I have been measuring the caps and the test fine, but it seems the secondary of the transformer is shorted (measuring 0.1 ohm).

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 11, 2021, 03:29:30 pm
content: The transformer will tend to have low resistance. More likely one of its outputs has a shorted load?Tim

author: perieanuo
author_rank: Frequent Contributor
timestamp: March 12, 2021, 08:17:20 am
content: 0.1 ohm on secondary winding is normal.usually is the smps acting abnormal, like dead/shorted viper (my first doubt)anyway, check the smps outputs for shorts (diode d4 and diode from his left, rails 5V and 18V (maybe you got 18V shorted, like dome dead inverter on tis rail)

author: chema.rb
author_rank: Contributor
timestamp: March 12, 2021, 11:04:27 am
content: I've been testing caps, the 7805... everything measures fine. Everyting points to the VIPer12A.
Hoover stopped working - supply problem - Page 1
Forum section: electronics / repair

author: kbm
author_rank: Newbie
timestamp: May 07, 2024, 06:26:30 pm
content: Hoover was working and suddenly switched off. I changed the socket but didn't help. I dismantled the hoover and all circuits are connected. Nothing is burnt. Motor is not burnt off either. How to find where the problem is?

author: m k
author_rank: Super Contributor
timestamp: May 12, 2024, 07:33:56 pm
content: Maybe engine is brushed and brushes are worn out.Or induction type and capacitor is worn out.

author: SeanB
author_rank: Super Contributor
timestamp: May 12, 2024, 08:19:48 pm
content: They normally fail because the cable reel gets poor contact, the actual cord itself breaks internally, or the motor brushes wear out. Multimeter to see continuity on both cores of the cable to the switch, continuity through the switch, and if the resistance across the motor is needed. Cable will be under 2 ohms generally, the same for the switch, and for the motor generally anything under 30ohms means it is fine. But most common is brushes sticking, which means no operation, and you either get new brushes, around 3 pounds, or a new motor, or a new vacuum cleaner.Very rare for the speed controller to wear, but it is possible the speed control is intermittent, and does not contact at some point on the track. If so then you will need ot fix speed control, though most of the time you run at full power anyway.

author: kbm
author_rank: Newbie
timestamp: June 29, 2024, 04:01:10 pm
content: I replaced motor with a new one and the hoover works.
Horizon Electronics Titan or Testron power supply manual - Page 1
Forum section: electronics / repair

author: kleinwaechterj
author_rank: Newbie
timestamp: March 27, 2021, 05:20:31 pm
content: Hi, I am looking for a user and/or service manual for a Horizon electronics Titan TSPS power supply. The newer Testron power supplies have an identical looking front panel, so a Testron manual might help to. Really, what I am looking for is how to operate the front panel and ideally for a listing of the goin commands for remote programming. I would be super grateful if someone could help, I am kind of struggling.Thank youJK
Horizontal black lines on screen - Page 1
Forum section: electronics / repair

author: Theo123
author_rank: Newbie
timestamp: June 19, 2023, 10:26:02 am
content: Hello EveryoneI need your help to repair my poor Samsung TV which decided not to let me watch my favorites series in the afternoon. Suddenly black horizontal lines appeared on the screen making my life a hellPhoto:https://ibb.co/Kyhm9M5Close up photo:https://ibb.co/zNtv4XPI have seen many youtube videos with guys who put a tape in ribbon cable and TV fixed in a magic way (I have tried without success).My TV model is: LE46C750R2WPhoto:https://ibb.co/Q6RFN94I have tried to disconnect one ribbon cable at a time to see what happens on the screen. unfortunately didn't happened what always happened on movies where everything is fixed in a real magic way and everyone is happy running laughing through green meadows. When i disconnected the right ribbon cable I saw on the right half of the screen the content with horizontal lines. The left half was white.Photos:https://ibb.co/zSRS3bVWhen I disconnected the left ribbon cable I saw the right half of the screen just white and the left half black.Photos:https://ibb.co/4gp6PYsT-con boardPhotos:https://ibb.co/Sn3h32Jhttps://ibb.co/WPmY3wYAnd I am wondering now. Am I a completely idiot looser who must be disappeared from earth face or there is a hope to help me one of this Team member ?Is T-com board for garbage or I need to put simple a tape in the correct pins on ribbon cable ?

author: m k
author_rank: Super Contributor
timestamp: June 25, 2023, 12:54:07 pm
content: Seems to be a memory problem, possibly just one power line.Other thing is how to find it and then repair it.
how do I adjust Horizontal Positioning on my scope? - Page 1
Forum section: electronics / repair

author: solder_boy132
author_rank: Contributor
timestamp: December 22, 2020, 10:52:51 pm
content: I calibrated the scope with the horizontal time base on my Tektronix 2235 oscilloscope, but when I powered it on again, the trace was shifted ti the left. I used the horizontal positioning knob to try and move it to the center, but the trace was still there. I probably read the service manual wrong and trimmed the wrong pot. I looked in the manual for the pot used to move the trace, but with no luck. So this is why i'm posting this.
Hot Air Station - Komec 908 Burned up - Page 1
Forum section: electronics / repair

author: sampler1
author_rank: Regular Contributor
timestamp: July 07, 2020, 12:46:03 am
content: Hi all,I have a Komec 908 Hot Air Rework station . It went up in smoke.. The OEM manufacturing installed a 15 amp fuse on the primary of the transformer instead of a 1.5 amp.. The transformer shorted and well you can guess.I have repaired all but the rear control board for the Hot Air has two resistors R7 and R10 that cannot be identified. Totally black and burned.Can anyone help me out with there value. I dont want to guess.

author: SpecialK
author_rank: Regular Contributor
timestamp: July 07, 2020, 02:46:20 am
content: My guess is something in the range of 10 ohms to 200 ohms. Super low value (less than an ohm) wont heat much with heavy current due to I squared R. High value (kilo-ohms, megohms) wont go supernova due to V squared over R. Obviously something else had to short in the circuit to subject these resistors to high voltage or current. I'm guessing that's the fan motor?R1 and R2 are 150 ohm. So that's my wild guess

author: sampler1
author_rank: Regular Contributor
timestamp: July 07, 2020, 08:06:32 pm
content: Quote from: SpecialK on July 07, 2020, 02:46:20 amThanks but Hummmmmm..

author: sampler1
author_rank: Regular Contributor
timestamp: July 07, 2020, 08:10:32 pm
content: The transformer was 24v 1.5A for the Iron and also 10V 0.8a for the hot air controller board. The transformer has already been changed. As for as those two resistors I was hoping to get lucky here. If not ill hook up two decade boxes and figure it out. I have Perdition's Flame up my ass!Cheers_________________

author: SpecialK
author_rank: Regular Contributor
timestamp: July 07, 2020, 09:36:17 pm
content: so do we know where the resistors are connected? Like are they in the path of the soldering iron heater, or the fan for the hot air? I might have a chance to look at my Sparkfun hot air tomorrow but it's strictly a hot air, no soldering iron.

author: sampler1
author_rank: Regular Contributor
timestamp: July 08, 2020, 12:34:28 am
content: One is connected to pin one of a Triac and the other pin one of an IC LM324N.all is on the Hot air side. I already have the Iron working.Thanks

author: TheMG
author_rank: Frequent Contributor
timestamp: July 08, 2020, 12:45:26 am
content: Looks like the TO220 part (TRIAC?) on the board has let the smoke out too. I wonder where the optocoupler comes into play in the circuit? Doesn't seem to have spared the rest of the circuitry from damage so it may not be for isolation?Anyways, if I had to guess what happened here, the TRIAC failed causing a cascade failure which eventually ended up with the transformer burning up. Very bad circuit design if that is indeed the case.
Hot tub controller trouble - Page 1
Forum section: electronics / repair

author: laban93
author_rank: Contributor
timestamp: November 22, 2023, 11:30:34 pm
content: Hi all!I have some issues with my hot tub controller. It works for 4-5 days, then freezes and the tub goes cold. Its irregular when it happens. I must turn it off for 5 minutes then back on to get it working. I also noticed that the LCD backlight was dim, and sometimes not working. I did try to fix it by re-capping both the controller pcb and the main pcb, but nothing changed.. any ideas of where to start looking? Or anyone with any experience fixing theese?

author: Runco990
author_rank: Frequent Contributor
timestamp: November 23, 2023, 06:23:02 pm
content: As someone who has fixed his own hot tub last year, have you looked at the control PANEL? I thought I had a bad main controller ($2000!!!) but it was the control panel that had corrosion in it. Seems they are not as sealed as you'd think.

author: laban93
author_rank: Contributor
timestamp: November 23, 2023, 07:48:34 pm
content: Yeah. I opened it and resoldered the connections and recapped. Did not see anything obvious though. It previousley had water intrusion trough the cracked membrane. Fixed that by silliconing a thin sheet of plastic as a second membrane. But yeah, there is no OBVIOUS faults.. When it freeze the buttons still work to control the jets etc, but the screen and heating turns off.

author: fzabkar
author_rank: Super Contributor
timestamp: November 23, 2023, 09:26:04 pm
content: It seems that the backlight might be a clue. Can you trace the circuit in this area?
How can i download content from Mass Production Tribe so i can repair SSDs? - Page 1
Forum section: electronics / repair

author: GabrielFerraz1776
author_rank: Newbie
timestamp: August 10, 2023, 04:00:01 pm
content: I'm a computer Engineer and i specialize in working with SSDs since i love how SSDs work and i started repairing them i do have multiple tools such as many MPTools from many manufacturers, however i need a few that i can only find in chinese website but i cannot access it. Does someone has access to it so i can PAY/Buy to have access as well. i'm open to whatever pricetag, i just need it.As we can see in the link below we see many people linking back to that chinese website which doesnt allow me tor register or anything.https://blog.csdn.net/2301_77321575/article/details/132026391?spm=1001.2014.3001.5502Which they as to go to "http://club.liangchanba.com/thread-1812-1-1.html" but i never loads and i can't access itThe files i needMPTools or as they're known IG5236 card activation software, that one is for Innogrit's Rainier Controller the IG5236MPtools for Maxiotech MAP1602 as we can see belowhttps://blog.csdn.net/2301_77321575/article/details/131242747?spm=1001.2014.3001.5502http://club.liangchanba.com/thread-1811-1-1.html
How can I find 2Hz volume wobble in 5.1 stereo system ? - Page 1
Forum section: electronics / repair

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 11, 2019, 10:18:37 pm
content: I have a little Logitech x-540 5.1 surround system for my computer, and it has a problem sometimes, like the output has some tremolo guitar pedal type effect, or some phasor pedal effect, that is at around 2 times per second, 2Hz. It was like it from the day I got it, years ago. And it's not the PC, trust me.The easist way to hear it is, if any sort of white/brown//etc noise is playing, on any speaker (it happens on each speaker on it's own) and the physical volume potentiometer of the logitech, is at a certain place and the problem happens, it will sound like the volume is going up and down a bit, like pulsating. I haven't figured out if the volume actually is going up/down, or if it just some interference type effect.I can hear that's it's about 2Hz, that's always the same, so is the intensity change/per volume, so the higher the volume, the more obvious the problem. At least I don't notice it most of the time, regular speech, parts of games, etc, u just won't notice.Now if I wiggle the volume pot up/down a bit, I can often get rid of it.Looking at the direct output from the logitech amp, to 1 of the speakers, last year, On my Tek 2215 and Tek2430A, I can't make out anything at all, working normal or not. It's just super low voltage jumble. And worst of all, at 2Hz, my scopes are pretty ugly looking, I hate using them at 60Hz, you still don't have a nice smooth beam.Maybe I should solder in a set resistor for a while and see if it happens then ? It would be super lucky and easy if it's just the volume knob pot that's the problem.If it is some sort of transistor based oscillation, IDKOther than that, it's a pretty cheap and basic circuit, with 1 big output chip, that does pretty much everything, just add some big caps.On a side mission, I could try making some audio meter type circuits. I want some of them.
How can I obtain the data sheet of LCD chip RT6935 and RT6939? - Page 1
Forum section: electronics / repair

author: daisizhou
author_rank: Super Contributor
timestamp: October 17, 2024, 05:41:10 am
content: Hello everyoneChip models RT6935 and RT6939 are shown in the figure below.They come from the LCD TV logic control board,I can't get the detailed data sheet, if you can find it please help me, thanks

author: fzabkar
author_rank: Super Contributor
timestamp: October 17, 2024, 09:39:58 am
content: https://www.digikey.kr/htmldatasheets/production/1987165/0/0/1/RT6239-A-B-Datasheet.pdf

author: daisizhou
author_rank: Super Contributor
timestamp: October 17, 2024, 10:01:56 am
content: Thanks.But it seems that they are not the same model, they may be produced by the same manufacturer

author: fzabkar
author_rank: Super Contributor
timestamp: October 17, 2024, 10:04:37 am
content: I couldn't find RT6935, and Google autocorrected my spelling for the RT6939. Sorry.
How can I test ICE2QR4765 without an oscilloscope  - Page 1
Forum section: electronics / repair

author: abdolah
author_rank: Regular Contributor
timestamp: May 12, 2024, 09:18:06 am
content: Hi everyone hope you having a fantastic dayI wanna to ask if I can test this IC (ICE2QR4765) , it's an smps pwm controller , to make sure that it's fully working without an oscilloscope, I have my multimeter with frequency meagrment , and I have my power supply 15v 1A ,

author: Harry_22
author_rank: Frequent Contributor
timestamp: May 12, 2024, 01:23:00 pm
content: Hi! You can measure p-n diode structure from CS to Drain for breakdown.And also the supply current in normal operation should be around 1.5 mA. I am not shure regarding ZC pin but CS in this case must be connected to ground.But why do you need to test the controller separately?

author: DavidAlfa
author_rank: Super Contributor
timestamp: May 12, 2024, 01:56:12 pm
content: If you're replacing it and have fear that the new one is fake or bad and might blow everything up, connect it with a 100-500W resistive load in series with the mains input (I.E. a light bulb or a heater) so it limits the current, avoiding a destructive short.Plus the light bulb will provide visual feedback if there's a short.If you're troubleshootign a non-working device, the internal mosfet is very unlikey to go bad without catastrophic consequences, 99% of the time it'll blow up the entire thing.If the fuse isn't blowing up on, start by measuring voltage in FB and VCC pins.But remember it's mains voltage, so be safe!The circuit in these is quite simple, so it should be pretty easy to trace the issue.A shorted rectifier or diode, broken resistor, bad optocoupler...If the old one blew up, the current sense resistors (Connected to CS pin) usually go bad too, so check them.

author: abdolah
author_rank: Regular Contributor
timestamp: June 01, 2024, 02:08:59 am
content: Sorry for the late response, I was having a hard time 😞My PSU is trying to start but it stops for some reason I have changed all caps with good ones replaced p223 supervisor IC replaced the 5v and 3.3v ic MOSFET controller

author: abdolah
author_rank: Regular Contributor
timestamp: June 01, 2024, 02:20:06 am
content: Yes I'm repairing my PSU, and the issue is quite complicatedFirst the PSU was not starting then I checked some components and found a 10ohm resistor that was open and I replaced it the the power supply work on it self when I pluge the mains without the pson signal , then I thought it's a supervisor IC problem then I replaced it and now it's powering on for half a second then power off , the I replaced the 5v and 3.3v controller and the sameproblem
How can I test power generator in the PCB of CRT TV? - Page 1
Forum section: electronics / repair

author: bshi02
author_rank: Regular Contributor
timestamp: March 30, 2024, 02:10:17 pm
content: Hello.I tried to fix CRT TV(21fu1r-ns of 220 voltage) which I got from a recycling bin.Unfortunately It is impossible to power on this CRT TV.So I dismentled this CRT TV, and I found that its fuse never have been blown and Voltage of big capacitor(main filter capacitor) is 315v and It seems that this big capacitor barely discharged after a couple of days.I successfully detached all of its PCB from cathode ray tube, and I measured all of resistor in HOT area and compare its value to each resistor in the MC059C schematic. which is the same part number with CRT TV's PCB I have.https://i.redd.it/m0b68t9i9drc1.jpgIt seems that all of resistor in HOT area is somewhat the same with each resistor in the MC059C schematic.So I need to test power regulator of STR-W6754 whether it really works or not.But I heard that, In order to power regulator in CRT TV's PCB, I have to switch on CRT TV.Is there any method to test power regulator in CRT TV's PCB whitout swtching on?And Should I connect all of connector in the PCB to cathode ray tube before I switch on?If I switch on CRT TV's PCB without connecting any connector to cathode ray tube, Then It would cause broke down or burst in CRT TV's PCB?Any reply would be appreciated.

author: inse
author_rank: Super Contributor
timestamp: March 30, 2024, 04:21:32 pm
content: I suggest to leave everything connected.Start checking the supply voltage of the controller circuit IC801.There’s a diode and two resistors from the bridge rectifier, those make the startup supply (can’t read the reference numbers).I don’t have the datasheet of it, but I would expect something like 12V at the IC pin.As the main capacitor is not discharged in days, I suspect that possibly one of the resistors is broken.Be careful probing the live circuit, best practice would be having an isolation transformer.
[Solved] How do fix error problem in Richmeter RM219? - Page 1
Forum section: electronics / repair

author: AkibUddin
author_rank: Contributor
timestamp: November 08, 2022, 10:52:25 am
content: Yesterday try to update battery power system 2xAA to 3.7V 800mah battery, suddenly meter show me this messagenow totally confuse about itany one have any solution idea ?

author: tunk
author_rank: Super Contributor
timestamp: November 08, 2022, 11:04:53 am
content: Does it work if you put back the AAs?The fully charged voltage of the 3.7V cell probably is 4.3V - that may have damaged your meter.

author: AkibUddin
author_rank: Contributor
timestamp: November 08, 2022, 04:47:15 pm
content: yes,already try it using 2x-AA battery but still same ErrE message showing and instant power off

author: AkibUddin
author_rank: Contributor
timestamp: November 29, 2022, 08:53:45 pm
content: Quote from: tunk on November 08, 2022, 11:04:53 amThis problem come from eeprom 24c02adeathnow try to give another soul into rm219
How do I calibrate my Tektronix 2235 - Page 1
Forum section: electronics / repair

author: solder_boy132
author_rank: Contributor
timestamp: December 19, 2020, 08:05:10 pm
content: Recently bought my first oscilloscope from ebay. Its a tektronix 2235. 100MHz. It functions well. It seems healthy. When i fed in a square wave, it looked fine. But the gain was a little bit off. Time base as well. I asked Tektronix for the service manual and kindly did. I looked through and couldn't find how. Im familiar to high voltage CRTs so no worries on opening it up. Pls help. I Checked the CRT voltage and the meter went

author: bdunham7
author_rank: Super Contributor
timestamp: December 19, 2020, 08:09:21 pm
content: Quote from: solder_boy132 on December 19, 2020, 08:05:10 pmThe 2235 is not digital. You have to use an analog meter.

author: bob91343
author_rank: Super Contributor
timestamp: December 19, 2020, 08:27:04 pm
content: How are you measuring the gain?

author: solder_boy132
author_rank: Contributor
timestamp: December 19, 2020, 09:29:19 pm
content: I did. use an analog. Set voltage setting wrong.

author: solder_boy132
author_rank: Contributor
timestamp: December 19, 2020, 09:30:32 pm
content: Well thats what im guessing.

author: bdunham7
author_rank: Super Contributor
timestamp: December 19, 2020, 09:55:23 pm
content: Quote from: solder_boy132 on December 19, 2020, 09:30:32 pmYou say you have 'experience' with CRTs yet you aren't aware that there are thousands of volts behind that shield and over 10KV at the anode. On the off chance that you are serious here, the various adjustments required to calibrate the scope are scattered all around inside with most of them on the attentuator (input) board. How to adjust them is found in Section 5 of the service manual. Leave the high voltage shield in place unless there is a problem. The issues you are reporting have nothing to do with the CRT HV circuits. In case you didn't get aservicemanual, it is here:https://w140.com/tekwiki/images/3/30/070-4206-00_2235_Service_Manual.pdf

author: jdragoset
author_rank: Frequent Contributor
timestamp: December 19, 2020, 10:49:37 pm
content: At the least, a working tektronix 067-508 amplitude calibrator and time marker generator 184.These could likely be substituted with a calibrated DVM, frequency counter and square wave oscillator.

author: David Hess
author_rank: Super Contributor
timestamp: December 19, 2020, 11:31:19 pm
content: Vertical calibration can be done with a function generator, AC voltmeter, and RF attenuator to make calibrated precision square waves. Complete horizontal calibration requires an RF signal generator or at least square waves up to 20 or 50 MHz, but rough calibration can be done with lower frequencies.Before messing with the calibration, verify how far out of calibration it is.
how do I cap a pair of short electrical wires ? - Page 1
Forum section: electronics / repair

author: Hextejas
author_rank: Frequent Contributor
timestamp: May 18, 2020, 04:41:40 pm
content: This connector had 4 wires coming from it and I only needed 2 so I cut the other 2 off. Now I got the potential for a nasty shock unless I can figure out a way to cap them off. The 1st thing that came to mind was a small wire nut but maybe there is a better way.Any ideas ?

author: Labrat101
author_rank: Unknown
timestamp: May 18, 2020, 04:54:49 pm
content: . Hot glue works well. and has a high insulation factor. not so pretty .Can rape some tap round first an then inject the hot glue in when cold remove the tapeand you should get a nice molded finish .or if you require something a little stronger epoxy resin ( Not the Metal epoxy)Use scotch tape makes a good molding frame.

author: propman
author_rank: Newbie
timestamp: May 18, 2020, 05:03:13 pm
content: Heatshrink

author: Hextejas
author_rank: Frequent Contributor
timestamp: May 18, 2020, 08:30:37 pm
content: Quote from: Labrat101 on May 18, 2020, 04:54:49 pmThats a really good idea, thanks. I might just combine it with the heat shrink and see how it turns out.

author: Hextejas
author_rank: Frequent Contributor
timestamp: May 18, 2020, 08:31:22 pm
content: Quote from: propman on May 18, 2020, 05:03:13 pmThank you Propman.

author: telectric
author_rank: Contributor
timestamp: May 18, 2020, 09:00:22 pm
content: Make the heat shrink a quarter inch (6mm) or so longer and while it is still warm pinch together the extra length with a pair of pliers. The two sides will stick together and make a seal. If you use heat shrink with an internal adhesive it will not come of easily either.Tracy

author: Gregg
author_rank: Super Contributor
timestamp: May 18, 2020, 10:45:30 pm
content: Pop the connectors out of the housing one at a time and trim the stubby wires as close as possible with flush cutters. You may have to straighten out the locking prong on the crimp connector to get it to click in place properly.

author: tkamiya
author_rank: Super Contributor
timestamp: May 22, 2020, 05:36:53 am
content: I typically leave wires little longer and heat shrink it.Can you remove the pin? Then you really don't have to worry about them.
How do I classify this transformer? - Page 1
Forum section: electronics / repair

author: Skyfox
author_rank: Regular Contributor
timestamp: January 08, 2023, 10:58:23 pm
content: Hi all,I'm trying to fix a tiny little fluorescent tube driver circuit and it has this transformer in it. I made up a schematic symbol for it below to illustrate what I'm talking about. One side has 3 pins with the primary winding on the end pins. The other side has 2 pins with two secondary windings which meet up at the center pin on the opposite side. I've seen plenty of 5-pin transformers that have two windings and a center tap on the same side, but I've never seen one where their center tap is on the opposite side. I've included the wire diameter and the resistance of each winding but I have no idea how many turns are on each one, especially the inner winding with the thinnest wire.How do I classify this transformer in order to find a replacement?

author: coppercone2
author_rank: Super Contributor
timestamp: January 09, 2023, 06:00:52 am
content: the general class is I think called ferroresonant transformer (for LCD tubes). Maybe you can find similar pinouts searching that term

author: Swake
author_rank: Frequent Contributor
timestamp: January 09, 2023, 03:29:06 pm
content: Looking for application notes in the datasheets of the chips around that thing.If that transformer is 'dead' it is likely that one or more resistance measurements are not as build anymore. Especially if some part melted.If you think your measurements are trust-able and as you know the diameter you could calculate the length of the wire based on the resistivity of copper.https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: January 09, 2023, 05:22:12 pm
content: If this is your circuit, you may not need the small secondary since it would be a brightness control:https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse2.mm.bing.net%2Fth%3Fid%3DOIP.2Q9pvdLy0pLmppyyvgIs2AHaDv%26pid%3DApi&f=1&ipt=c4132c4695346ef5ed3e0452ee336b0b8c4ad76f95c3da6a60e36e72f9935a58&ipo=images

author: james_s
author_rank: Super Contributor
timestamp: January 09, 2023, 07:49:32 pm
content: It's most likely a custom wound transformer for that specific device. There is no set standard for the pin layout, if you're designing a custom transformer you can specify whatever pinout makes your PCB layout convenient.
How do I determine diodes from SMD markings? - Page 1
Forum section: electronics / repair

author: lukes
author_rank: Newbie
timestamp: May 31, 2019, 01:40:09 pm
content: My parents have a pool controller (Pentair Intellitouch) where the RS485 transceivers were blown from an indirect lighting strike. This is the second time this has happened and we don't want to pay $500 for a new board so I am going to try an solder on new Maxim MAX1483 RS-485 transceivers to see if that fixes it. The weird thing is the "A" line of the two transceivers are tied together and to a diode, the same is true for the "B" line to the other diode. The other side of each diode is tied to ground. The are components appear to be diodes, the multimeter thinks are didoes in diode mode. The silkscreen of "V1" and "V2" made me think they are MOV but would that read in diode mode on the multimeter? I would like to replace them as well but don't know how to determine the specs of them and what type of diodes they are.Any idea how I can determine what the specs are for these diodes from the markings on the chips?Line 1: P03ALine 2: 4AHS5See attached pictures as well

author: Miti
author_rank: Super Contributor
timestamp: May 31, 2019, 03:12:25 pm
content: P03A is actually what you're looking for, no translation is needed. It is a SIDACtor protection thyristor. Just google it.

author: lukes
author_rank: Newbie
timestamp: May 31, 2019, 04:08:51 pm
content: Thanks Miti! I did a google search and was getting a lot of noise but couldn't narrow down exactly the part, one I typed P03A thyristor I was able to find the exact part.
How do I disconnect this flat flex? - Page 1
Forum section: electronics / repair

author: Lomax
author_rank: Frequent Contributor
timestamp: August 07, 2021, 09:57:25 am
content: Hi all,Not familiar with this type of FFC connector - having had a gentle poke it neither seems to flip up or pull out. Anyone know the correct way to open it?

author: eb4fbz
author_rank: Regular Contributor
timestamp: August 07, 2021, 11:51:14 am
content: Flip the brown latch upside

author: Audiorepair
author_rank: Frequent Contributor
timestamp: August 07, 2021, 12:20:03 pm
content: i think you pull the two white ears away from the connector.

author: geggi1
author_rank: Frequent Contributor
timestamp: August 07, 2021, 12:22:03 pm
content: It looks like something something I have seen in my Samsung LCD tv and in Motorola PMR radio gear.The brownish piece of the connector is keeping the pressure on the flex and the white squares on the sides are locking the brownish part.The white is either to press down or press inn, most likely to press inn.

author: Ian.M
author_rank: Super Contributor
timestamp: August 07, 2021, 01:02:47 pm
content: The radius curve on the end of the brown part is a pretty good indication that it flips up. If it is unwilling to do so with moderate lifting force on its edge where the flat-flex enters, try lifting it while pressing down on the outer ends of both white tabs.

author: Lomax
author_rank: Frequent Contributor
timestamp: August 07, 2021, 01:28:58 pm
content: Thanks guys - in the end I was too impatient and chose to fix the boards in place with a piece of styrofoam and some tape while doing the repair, so I didn't need to disconnect the FFC. Would have been fiddly to reconnect due to short cable...

author: Audiorepair
author_rank: Frequent Contributor
timestamp: August 07, 2021, 01:33:35 pm
content: Spoilsport

author: Lomax
author_rank: Frequent Contributor
timestamp: September 19, 2021, 02:41:28 pm
content: Me again! And this time I really have to disconnect the FFC - though it is a different connector: some Omron jobbie that I can't figure out how to open. Don't want to use any kind of force in the wrong direction/on the wrong part!

author: Lomax
author_rank: Frequent Contributor
timestamp: September 19, 2021, 02:42:44 pm
content: Ha! After posting this I looked at the picture again - it's pretty obvious really: just flip up the black part at the back!
How do I remove a (crimped??) thermal switch - Page 1
Forum section: electronics / repair

author: niconiconi
author_rank: Frequent Contributor
timestamp: June 16, 2021, 08:17:35 pm
content: Hi all.As shown in the picture, I suspect this KSD301 thermal switch in a coffee machine is defective and I want to remove it for a check. But I don't see any solder on the joint, is it aclampedcrimped connection? If so, is there a way to nondestructively remove the switch?Note: in the second picture, the slot-like object is actually the end of the multistrand wire, it's not a connector slot.

author: Ian.M
author_rank: Super Contributor
timestamp: June 16, 2021, 08:44:14 pm
content: You can't non-destructively. The wires have crimped on ferrules which are spot-welded to the switch terminals which in turn are riveted to the switch.Connect a suitable test lamp (e.g. a neon indicator with integral series resistor) across the switch and try operating the unit. If the test lamp lights up and the switch isn't over 95 deg C, its failed open and should be replaced. If it doesn't light up, its probably still good unless you are certain the switch is over 95 deg C.Repacement would involve cropping the wires right at the ferrules, crimping on female spade connectors aNd pushing them onto the lugs of a new switch.

author: amyk
author_rank: Super Contributor
timestamp: June 17, 2021, 01:22:31 am
content: They are too cheap to even use female spade terminals like that part was originally designed for.

author: TheMG
author_rank: Frequent Contributor
timestamp: June 17, 2021, 02:07:21 am
content: Quote from: amyk on June 17, 2021, 01:22:31 amIn these days of mass manufacturing and maximizing profit... every penny matters.Just cut the wires off and crimp some terminals on there to connect the replacement, if it does turn out to be bad. As for testing... it's a switch, no need to remove it from circuit for testing. A DMM is all you need unless you suspect its temperature range is no longer accurate, then a thermocouple would be handy too.

author: BrokenYugo
author_rank: Super Contributor
timestamp: June 17, 2021, 02:59:16 am
content: Quote from: amyk on June 17, 2021, 01:22:31 amI'd rather they weld them, seems those switches are often killed by the spade connectors developing bad connections and heating the switch from the wrong end.

author: perieanuo
author_rank: Frequent Contributor
timestamp: June 17, 2021, 02:16:02 pm
content: we can see the solder, just unsolder the pinbtw,, that thing when it breaks, it doesn't close anymore correctly his contact (so your ohmmeter will see more than 0.3 ohms), or it cuts off at wrong temp, the voltmeter will tell you the truth. can't really do repairing without them aren't we?
How do I repair my Yihua 992DA or what should I replace it with? - Page 1
Forum section: electronics / repair

author: bitogre
author_rank: Contributor
timestamp: August 09, 2020, 11:21:14 pm
content: My wife got me a Yihua 992DA because she was concerned about me being exposed to solder fumes. It works for a while but the fume capture did not work that well. After a year, a friend used it and overheated the hot air wand. Now, when ever I plug it into a GFI circuit and turn it on, the GFI pops, even with the Hot Air off. If I plug it into a non-GFI outlet, the soldering iron works fine (including the fume suction no worse than before). This makes me think that something in the Hot Air wand is connecting to ground. I am wondering if I should try fixing it, leave it as is and get a separate hot air gun, or replace it completely. If I should replace it, what should I replace it with (budget about $150)? I do need an iron that can solder large wires (putting XT60 connectors onto 10 AWG wire).
How do you crimp hard-shell insulated connectors? - Page 1
Forum section: electronics / repair

author: ggggizli
author_rank: Newbie
timestamp: October 11, 2024, 07:57:13 pm
content: I ran into exactly the same problem with my Thermador microwave as this guy (https://www.eevblog.com/forum/repair/ge-microwave-oven-with-burnt-connectors-on-thermal-cutoffs-(usa)/) Like many pointed out in that thread, the problem seems to be bad quality connectors on the TCO.I have a dumb question before I jump in and start ordering parts. How do you crimp hard-shell plastic insulated connectors like shown in attached picture? Is the insulation supposed to be removable? Are there specialty tools that let you do that?

author: inse
author_rank: Super Contributor
timestamp: October 11, 2024, 08:11:27 pm
content: You only crimp the exposed metal tab, possibly it’s slipped into the isolation afterwards.You need a crimping tool for unisolated connectors, don’t try it with the red/blue/yellow pliers.

author: MarkF
author_rank: Super Contributor
timestamp: October 11, 2024, 08:21:26 pm
content: Ya, you only crimp the metal part. Then it clips into the plastic shell.I just ordered these from AmazonPreciva Dupont Ratcheting Crimper Plier Set. Notice the rounded crimp at #3 in this picture. It forms the proper round crimp on the wire insulation. Areas #1 and #2 form a wedge shape which doesn't work on the insulation. I have another crimp tool where the insulation crimp is the wedge, 'W' shape, and for Dupont end they don't slip into the shell most of the time.You need to check the size of your connector if it can be crimped with a Dupont crimp tool. But, you will need to look for the rounded area for the insulation and the 'W' area for the wire.

author: tooki
author_rank: Super Contributor
timestamp: October 11, 2024, 08:52:34 pm
content: Quote from: MarkF on October 11, 2024, 08:21:26 pmThat is incorrect advice.Most open-barrel crimp terminals are designed to have the m-shaped (“type F”) insulation crimp. DuPont connectors are one of the exceptions that require the circular insulation crimp — you see this because of the pointed, angle-cut insulation wings.The terminal shown in the original post has insulation wings that are cut square, which are typically used with the m-shape crimp (but which can often use the circular crimp).Edit:Anyway, OP amazingly didn’t bother to link to the terminal in question in this thread about crimping it, but at least did so in the other thread. It is a 0.25” Faston for 18-14AWG wire, so it is FAR too large a terminal for that crimp tool linked above. A DuPont contact is under half the size of this Faston.There are any number of affordable crimp tools for open-barrel terminals that should work for this.Here’s the terminal drawing:https://www.te.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Customer+Drawing%7F521011%7FK3%7Fpdf%7FEnglish%7FENG_CD_521011_K3.pdf%7F521011-1
How do you open this relay - Page 1
Forum section: electronics / repair

author: thinking
author_rank: Newbie
timestamp: October 03, 2020, 12:14:41 am
content: HiI'm replacing the power cord on my Storz and Bickel Volcano. I've tracked the power cable inside the unit and to this relay but I can not figure out how to open it.Sorry for any ignorance. I have no background in electronics.

author: shakalnokturn
author_rank: Super Contributor
timestamp: October 03, 2020, 12:22:40 am
content: If you're referring to the grey / green / orange thing it isn't a relay.You release the wires by pushing down on the metal visible on the photos with a small flat screwdriver while pulling lightly on the wire.

author: thinking
author_rank: Newbie
timestamp: October 03, 2020, 12:42:41 am
content: thank you
How do you remove the main board from an Onkyo receiver (A-RV401) - Page 1
Forum section: electronics / repair

author: onedumbquestion
author_rank: Contributor
timestamp: July 07, 2023, 01:32:47 pm
content: I'm forced to work on this board attached to all sorts of stuff it's so frustrating I wanna disconnect the board and put the everything else to the side while I repair the board Has anyone done this There are pins with bare wire wrapped spiral and other white connectors with grey ribbon power cables that I don't know how to disconnect either

author: kingswoods
author_rank: Newbie
timestamp: July 08, 2023, 01:58:38 am
content: The grey ribbon wires come off by pushing down on the top of the white connector and this releases the wires.
how do you troubleshoot an Ic(ssc9522s) with a multimeter? - Page 1
Forum section: electronics / repair

author: Jekgbg
author_rank: Contributor
timestamp: August 11, 2024, 08:09:03 am
content: Hihow to trobleshooting this IC (ssc9522s)with a multimeter ?https://acrobat.adobe.com/id/urn:aaid:sc:EU:096f04f8-816f-4fb2-a845-cccec1af9efd

author: indeterminate
author_rank: Regular Contributor
timestamp: August 11, 2024, 10:07:06 am
content: 1 get a copy of the data sheet2 se if pin 2 is being supplied the correct voltage3 se if pin 8 is supplying your gate drive voltage4 se if pin 1 has ac voltage on itmake shore there are no external shutdown signals present

author: fzabkar
author_rank: Super Contributor
timestamp: August 11, 2024, 04:16:32 pm
content: Datasheet:https://www.semicon.sanken-ele.co.jp/sk_content/ssc9522s_ds_en.pdf
How does the DSP chip read or write programs? - Page 1
Forum section: electronics / repair

author: daisizhou
author_rank: Super Contributor
timestamp: May 17, 2021, 02:51:29 am
content: Completed

author: ataradov
author_rank: Super Contributor
timestamp: May 17, 2021, 03:21:01 am
content: There are tools from TI, you can find them by going to the DSP page. But it is highly likely that the cheap is locked from reading, and you won't get the firmware from the working one.
How does this diode work? - Page 1
Forum section: electronics / repair

author: naujoks
author_rank: Regular Contributor
timestamp: October 02, 2024, 12:06:47 pm
content: I'm trying to repair an early 90s PC PSU, which has no +5V.There is a dead short on the 5V rail.I found out that when I take the diode S30SC4M out of the circuit the short disappears.I can measure a short between pin 2 and 3, but not between pin 1 and 2, so my assumption is that this diode is faulty.I'm not familiar with this kind of diode and I'm interested in how it works. It seems to have two diodes wired against each other, so does that in effect make it a transistor, or a MOSFET?Interestingly, when taken out, the PSU also doesn't have 12V output. Is that the expected kind of behaviour how it works, that it's responsible for the 5V and 12V output, and maybe the other voltages too?

author: langwadt
author_rank: Super Contributor
timestamp: October 02, 2024, 12:13:39 pm
content: It's just two diodes in one package

author: naujoks
author_rank: Regular Contributor
timestamp: October 02, 2024, 12:20:25 pm
content: I see. So it makes sense then that the left hand side is in the 12v circuit and the (shorted) right hand side is in the 5v circuit.

author: langwadt
author_rank: Super Contributor
timestamp: October 02, 2024, 01:15:28 pm
content: Quote from: naujoks on October 02, 2024, 12:20:25 pmthe diodes are connected, 5V and 12V wouldn't be cconnected like that

author: naujoks
author_rank: Regular Contributor
timestamp: October 02, 2024, 02:30:17 pm
content: Is there any obvious reason why without that part the 12v line should disappear as well?

author: coromonadalix
author_rank: Super Contributor
timestamp: October 02, 2024, 03:02:46 pm
content: is the 5v derived from the 12vdc and removing theses diodes kills it ??is it possible to take some pictures or a crude hand sketch ?

author: wasedadoc
author_rank: Super Contributor
timestamp: October 02, 2024, 05:00:19 pm
content: Quote from: langwadt on October 02, 2024, 12:13:39 pmTwo diodes. Middle pin is their two cathodes.

author: fzabkar
author_rank: Super Contributor
timestamp: October 02, 2024, 05:55:22 pm
content: Seehttp://www.pavouk.org/hw/en_atxps.html
how does this power supply decade resistor network work? - Page 1
Forum section: electronics / repair

author: crazyhog
author_rank: Regular Contributor
timestamp: June 20, 2020, 11:32:29 pm
content: Hi all,I have a Power Designs 2005. The high precision output of the power supply is selected by a 4 decade resistor network. I understand the total resistance came from summing different combinations of resistors with 1, 2, 2, and 5 ohms (and their decade multiples). To get a particular output voltage, different voltage decade is used. For example, to get a 0.3v output, 300 ohm = 100 ohm+200 ohm. I've verified with a ohmmeter. Note that these are precision 0.1% resistors.However, the schematic is also showing a bunch of extra resistors (4.7, 6.8, 27, 18 ohm and their decade multiples). See the resistors circle in red. Furthermore these are10%resistors! I am really baffled by the purpose of these very low precision resistors. Why are they needed in this circuit?thanks,James

author: bob91343
author_rank: Super Contributor
timestamp: June 21, 2020, 12:10:48 am
content: That is strange. The style of drawing makes it a bit ambiguous but it seems those resistors are in parallel with the precision ones, and that makes no sense.

author: Ash
author_rank: Regular Contributor
timestamp: June 21, 2020, 05:13:27 am
content: Hi,You'll probably find it is a variant of a Kelvin-Varley divider.I have some bigger individual switched dividers like that.https://en.wikipedia.org/wiki/Kelvin%E2%80%93Varley_dividerCheers,Ash.

author: Nusa
author_rank: Super Contributor
timestamp: June 21, 2020, 10:05:53 am
content: Don't make the mistake of thinking 10% marking means the resistor actively changes its value during use. That resistormarked10% may actually have been selected as actually being very close to the nominal value.How can this be? One can take a bunch of 10% resistors and go through them with an appropriate measuring apparatus and find ones that are within the required specifications and only use those. It's calling binning. When it's done by the manufacturer, they mark them as precision and sell them for more. But you can get the same end result by doing it yourself.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 21, 2020, 10:22:41 am
content: Quote from: Nusa on June 21, 2020, 10:05:53 amSometimes - but as you said it is also done by manufacturers - so the 10% tolerance band could be all the resistors that were >5% but <= 10%, the 5% batch all those > 1% and <= 5% and so on.