Thanks, exactly the same problem, seeing your video, I ended up throwing everything in the garbage, not profitable financially and in time. You can find this set for 40€ second hand, anyway the sound wasn't very good, it's the opportunity to move on to something else. Thanks, I didn't realize how many dead components there were, I thought there were only 2, you've saved me a lot of time :) Hello from France
@Rolandpgbrooks
Жыл бұрын
I am following this with great interest. I have exactly the same issues with exactly the same subwoofer.
@martinschmidt959
8 ай бұрын
we really are looking forward to part 3 of this!
@hernancoronel
Жыл бұрын
PSU repair, Yeah! Love this videos, thank you Richard!
@pallanandor9163
Жыл бұрын
sir thanks for this detailed video!! I managed to fix the LG soundbar.Thank you very much for your help!!
@tonewheelkev
9 ай бұрын
Jus 'waking up' this post!! 😁 Great Part 1 and 2......will there be a part 3?
@שרוןבוכניק-ק4ל
9 ай бұрын
Hi, I had exactlly the same issue. I followed your excellent and professional guide and I managed to solved the issue. many thanks!!! 🙂
@elsaarmstrong-zp6ng
Жыл бұрын
Is there a part 3 episode coming?
@eleanordeboat4191
3 ай бұрын
Is part 3 on its way? I have the same unit and it now does not power on. The visible issue with it is different though, as the large snubber diode looks burnt. I have found a circuit diagram for the psu which will help immensly so i am about to start looking for other failures within the HV side.
@Lightrunner.
Жыл бұрын
Hi Richard 🤗🤗 Pay attention 17:52 dont take a X or Y condensator as a spare part for your faulty c. Nice repair video 🖖👌👍
@Dutch_off_grid_homesteading
Жыл бұрын
Heya, yhe most repair are only 1 or 2 components faulty but this 1 has quit a couple brooken components quit a challenge love to see this that wen you find 1 fault component you have to see if there are more faulty ones learned a lot from this.thanks
@julianhead1585
11 ай бұрын
Hi, I had exactly the same fault as described. Replaced all the components on the HV side, mentioned in the 2 videos, including the 3 zeners. A complete fix! (Nothing on the LV side changed). Probably wouldn't have been successful without the video. Excellent! Hopefully there will be a part 3 to show the actual fix?
@PaulHayesey
7 ай бұрын
Hi, which zeners did you use? I have the same board but am struggling to identify the zeners. I read off the markings using a magnifying glass and got: ZD901 = 3B51, ZD902 = Z223, ZD906 = 10C5T but I can't find these anywhere.
@PaulHayesey
7 ай бұрын
actually never mind, I found the schematic diagram for this power supply board which lists those diodes as: ZD901 GDZJ33B 33v 0.5W zener ZD902 GDZJ22B 22v 0.5W zener ZD906 GDZJ10B 10v 0.5W zener Just waiting for the PWM chip to arrive, the one I removed from my board was visibly cracked where I assume it has swollen up inside from something failing.
@baghdadiabdellatif1581
Жыл бұрын
Great work 👌👍
@tarotsuperstars
Жыл бұрын
There is a similar power board to this on ebay, but it's a LG SHS36-D. it' has the same large transformer but the board is a different size. The seller doesn't ship to anywhere but the UK though. It could be faulty too. I wonder if that one is in standby.
8 ай бұрын
Is there a part 3 coming?
@keithmarlow143
Жыл бұрын
Hey, thanks for the videos. I’m currently in the process of fixing a PWM controlled mains fan. Long story short I think a mains spike fried all semis on the mains side (bridge rect, 4 power switchers, viper12a and fuse) took off each and checked. Use lamp limiter on the mains and didn’t go out until the viper12a was removed. Just wondering what are the odds of what’s beyond the viper12a having survived? It’s the switching control chip. Looks like it’s being used to generate 10v and a 5v probably, two secondaries. I will check to see if any protection zeners are there, but I’m not impressed by the degree of transient protection, a few low value resistors, or TVSs in key places could have reduced the damage a lot. Get the impression the fan was meant to be installed behind a filtered mains source with its own fuse, not straight to dirty mains.
@PaulHayesey
7 ай бұрын
Did this ever get fixed? I have the same power supply board that appears to have failed in exactly the same way. The same capacitor and sensing resistors blown at least, I haven't got as far as measuring the various diodes yet. Just wondering if this ever got fixed.
@PaulHayesey
7 ай бұрын
Well, good news. I have my subwoofer fixed now. Replaced the PWM chip (visibly cracked due to internal swelling), 3x zener diodes (all measured off board as shorted), blown capacitor, small capacitor next to it (wasn't blown but possible heat damage), 2x 0.22ohm resistors, the large 120uf smoothing cap (not blown but discolouration on one side due to heat so thought it best to replace). I tested the transistor and the optoisolator off board and they were fine so didn't replace. Watching TV with good sound as I type this. Thanks for this video, pointed me in the right direction
@Dutch-linux
Жыл бұрын
zener diode 0c51 is a 5.1volts zener
@elsaarmstrong-zp6ng
Жыл бұрын
Interesting video but I think you need to insulate these long bare probes! Big risk of shorting if probes slip as I found from the past! I done mine right down to the point with heat shrink and sharpened the points to avoid slips!
@REVERSE_BIAS
Жыл бұрын
Are you saying that he's a bit wobbly with his probing??? Lol! 😂 Great guy, love his videos, but he probes as gently as a grizzly bear! 😂
@udadeni
Жыл бұрын
I am an electronics hobbyist who engages in electronics on weekends only. I have the exact same series subwoofer and exactly the same problem. initial inspection, IC 3BR0665, 2 red capacitors, few resistor (all in front of the IC) blown and some burnt PCB. I replace all damaged component and cabling the burnt PCB. but it still doesn't fixed the problem. after wasting 3x weekends, 3 time replacing IC but still not work. I usually try to fix thing back to original condition. but in this case i finally gave up and take shortcut by using '3-cable gacun'. 3br0665 must be removed before using Gacun. Problem fixed. I've try same solution to fixing LG LHD 657. Fixed also.
@andymouse
Жыл бұрын
"Gacun" Chinese ? name of a mine please ?
@udadeni
Жыл бұрын
@@andymousei can't find on international/china marketplace the exact same type that i use. As reference I think you can try search 'diymore QX YJ-4 Universal Power Module' Other reference you can also search Gacun on youtube
@dngdng7070
11 ай бұрын
Please share what Gacun you used - voltage and wattage. Where did you connect the third blue cable? Thanks .
@udadeni
11 ай бұрын
@@dngdng7070 I'm using gacun for 29 inch TV. Not measuring voltage or wattage. Blue cable connect to pin 4 optocoupler.
@ralphj4012
Жыл бұрын
As you say, there are issues around the voltage reference opto input and opto output section which would need to be reversed engineered to make any sense. Guesswork (check everything) C51 may be BZX79-C51, Z228 may be Excel Semiconductor 21.8V, 33BS etc see Semtech BS series datasheet.
@scottsmith5048
Жыл бұрын
Could that be a BZT33? If so that is a standard part number for a 33V zener diode with datasheet readily available.
@therealspixycat
Жыл бұрын
There was so much voltage on that blown cap that it may be arced out to the ?ground? blank wire that runs underneath the blown cap?
@gordthor5351
Жыл бұрын
You can see the screw head markings on two of the chips, so they must be pulls.
@anthonydenn4345
Жыл бұрын
Don't think that's 0C51, it looks more like 0C5T. Found (SMD), not (Through Hole) zener diodes marked 0C to be 5.2volts to 6volts! Not sure about the 5T part though. Maybe 5% tolerance, dunno tbh 🤔
@LearnElectronicsRepair
Жыл бұрын
It could be, it wasn't easy to read.
@anthonydenn4345
Жыл бұрын
@@LearnElectronicsRepair I had to watch it a few times 😄 But really it could be anything. I'm just going by the SMD reference, which this clearly isn't.
@kalulukakaluluka9497
Жыл бұрын
SMPS circuit diagram is sent to you Richard over E-Mail
@andrzejkolos9641
9 ай бұрын
ZD906 is Z10V
@will_doherty
Жыл бұрын
Not watch all of the video yet, but at 37:10 there are witness marks on a couple of chips where they have been screwed to a heatsink - so although the pins are very clean it does look as if those chips are pulls...
@LearnElectronicsRepair
Жыл бұрын
Yeah I do have my suspicions as mentioned. Doesn't mean they are bad, apart from one of them.
@will_doherty
Жыл бұрын
@@LearnElectronicsRepair Absolutely.
@ДанилаЛанцов
7 ай бұрын
Что в итоге было? После второй части видео прошло много времени, в результате удалось обнаружить все неисправности? Если выпуска 3 части не будет, напишите пожалуйста в комментариях, многие спрашивают и ждут развязки) У меня всё в точности так же, только не эт КЗ ни на шим ни где где то ещё, и никаких обугленных деталей, но следую вашим действиям и менять буду тоже самое, так как куда копать неизвестно) спасибо @@LearnElectronicsRepair
@richardrudek01
Жыл бұрын
I did not watch the first part. Have you tried testing the amp using your lab supply? I ask that because the discrete circuity your fixing obviously relates to power-control function. Now, I only noticed one opto-isolator. So, if the oc51 zener is indeed a 5.1V zener, then that suggests that they broke whatever isolation they had to implement the power-control from the amp. As we are talking about surges that have taken out much more robust, high voltage components already, this does not bode well for the low voltage circuitry (the amp)... 😒
@LearnElectronicsRepair
Жыл бұрын
I don't think it works that way - but this is all supposition: I would not be surprised to find that the PSU gives an output of maybe 5V when powered up due to the value set by the resistor divider and the TL431 when P-Ctrl is zero. Then the logic board sends a signal (voltage) which changes the setting of the TL431 which increases the output to the full working voltage when the subwoofer is working (24V or something maybe?) and puts the PSU back into standby output when it isn't working. This would be a kinda pseudo Standby using just one voltage rail from the PSU. I note the output is marked as VDD not any stated voltage. As the TL431 and associated circuitry is on the low voltage side, this could all be achieved with a single opto-isolator😉
@snakezdewiggle6084
Жыл бұрын
1 and a half hours !? Time and motion men will be on to you...
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