Powersupply board faulty, possibly not getting power

Thread Starter

ViruZHUN

Joined Jan 13, 2019
9
Hi!

I got a powersupply board from my LG oled55c7v. I dont got any warranty or anything. I found it at my local recycling station. When I press to start the TV it lights up for 1/4 second and shuts of. I suspected the powersupply. I tried to plug in the powersupply itself and test the voltages coming from the headers where the pins are. But when its plugged in I get zero voltage from all pins, some pins suppose to have 12 volts and some 24 but every pin is on 0 volts (A few are on like 0.07 volts)


here are pictures of the powersupply board: https://imgur.com/a/nCdc1av

The PCBs name is: eax67149611 (could not find any schematics)

You guys got any idea what the problem could be? and what I should do to find the faulty component(s) ?g

Note that I am new to electronics and but very interested in it and fixing stuff myself. I know a few basic components like capacitors, resistors, transistors etc but not all. So If u mention a component please tell me what it is in category :)
 

wayneh

Joined Sep 9, 2010
16,128
A TV power supply is usually under the control of various feedback loops and even a microprocessor. I'm not surprised that it doesn't do much when removed from the rest of the TV. It doesn't see whatever feedback it needs and stays dead. With a schematic and a service manual, you might have a chance of identifying whatever is going on. It's very hard, even for a skilled technician, without that information.

It's not clear - are you trying to fix the entire TV or just hoping to revive the power supply?
 

Thread Starter

ViruZHUN

Joined Jan 13, 2019
9
Thx for answer!

The entire TV. I thought the powersupply is fauly because it dont start the tv. but what do you recommend?
 

dl324

Joined Mar 30, 2015
9,331
but what do you recommend?
Reassemble the TV and troubleshoot in place. It'll probably be tedious if it'll only run for a quarter of a second.

It would be helpful if you traced the circuit and posted a schematic.

Cropped/brightened image:
powerSupplyBoard.jpg
 

Thread Starter

ViruZHUN

Joined Jan 13, 2019
9
I dont know how to trace yet. but I will research it. But Is it possible to trace even if the PCBs are multilayered?

Also. I reassembled the TV, connected everything. And started it, it turns off after 1-2 sec. But during those 1-2 sec I still get no voltage from the PSU, does this say something?
 
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