LG 50PG20 power issue (with pics)

[mazdaverx7]

i have an LG 50PG20 plasma television and the other night it randomly turned off in the middle of the game i was playing. it did not go to standby mode (no red light under the power button), it was like it was unplugged at that instant. i waited a couple minutes and the tv just turned back on all by itself. did this dance a couple more times and has been fine for a couple of days and tonight the ghosts came back to haunt the tv. my first thought was to faulty solder joints on the power supply board or bulging capacitors. no faults found that my untrained eye could see there. i have power from the wall to the tv.. any help from the experts would be most appreciated! here are some pics:

back panel removed from the tv:



power supply board:

[mazdaverx7]

Re: LG 50PG20 power issue (with pics)

sorry guys, would not allow me to manage to manage attachments and correct the vertical pics. i'll see if i can space them a shade more for easier viewing.

[PlainBill]

Re: LG 50PG20 power issue (with pics)

I'm not an expert, I'm not even allowed to play one on TV.

In the lower right corner is the connector to the main board. The contacts are identified, which helps. You are looking for one labeled PS/ON or something similar. If that is always on, the problem is in the power supply, or points toward the home circuit breaker. If that switches hi to low, the problem is on the main board.

PlainBill

[rmoody]

Re: LG 50PG20 power issue (with pics)

sorry guys, would not allow me to manage to manage attachments and correct the vertical pics. i'll see if i can space them a shade more for easier viewing.

They are likely larger than 2000 pixels vertical or horizontal. They have to be resized. I use the simple "paint" on windows.

[mazdaverx7]

Re: LG 50PG20 power issue (with pics)

i found tonight that when the tv turns itself completely off, if i tap on the top of the unit, it turns back on...strange.. leads me to believe i have a loose connection somewhere.. but i made sure all of the connectors were tight when i had the back off.

PlainBill, i'll do some more testing using your method. thank you for the advice!

[PlainBill]

Re: LG 50PG20 power issue (with pics)

i found tonight that when the tv turns itself completely off, if i tap on the top of the unit, it turns back on...strange.. leads me to believe i have a loose connection somewhere.. but i made sure all of the connectors were tight when i had the back off.

PlainBill, i'll do some more testing using your method. thank you for the advice!

Certainly - a bad solder joint, or bad cable, or bad power cord, or power cord not plugged in completely. I had one service call where the lady had carefully labeled every cord before moving. When she got to the new location, she carefully plugged in each power cord. On one of them the label interfered.

PlainBill

[mazdaverx7]

Re: LG 50PG20 power issue (with pics)

also of note, the television only powers off when in use, not when its in standby mode. i searched and the power supply board is still available. i may end up going that route if need be.

[mazdaverx7]

Re: LG 50PG20 power issue (with pics)

can anyone explain why the tv does not exhibit its shutting off symptom when in standby mode and only under the load from a video game, blu ray player or cable box?

[ipman]

Re: LG 50PG20 power issue (with pics)

When it's on, it will heat the boards and connectors. When in stand-by, it's cold.

[mazdaverx7]

Re: LG 50PG20 power issue (with pics)

makes sense. i'm thinking the relay on the main board is bad and when it heats up it turns the set off..

[PlainBill]

Re: LG 50PG20 power issue (with pics)

makes sense. i'm thinking the relay on the main board is bad and when it heats up it turns the set off..

Very unlikely. Start at the AC input connector and work your way to the bridge rectifier looking for questionable solder joints.

PlainBill