Help Needed. LG 42LC55

[drmore]

Hello
I Have an LG 42LC55 that has some issues.

It powers up, stays on for a random ammout of time then powers off.

Sometimes its will stay on for an hour other times only a few seconds.

Im guessing that the problem is in the powerboard. I have done a visual check and cant see any obvious blow caps however theres a yellow thingy that has some gunk leaking from it.

I have included some pic of the board in the hope that someone knows whats wrong with it.

Thanks
Jonathan

[PlainBill]

Re: Help Needed. LG 42LC55

The 'yellow thingy' is a transformer, the 'gunk' is varnish, and it is normal.

PlainBill

[drmore]

Re: Help Needed. LG 42LC55

haha guess i should get my school books out and work on my component recognition.

Well i think somthing might be overheating on the powerboard causing it to shut itself off for safety.

would really appreaciate it if someone more skilled than I could help shed some light on my issue

[tom66]

Re: Help Needed. LG 42LC55

I had this problem with my LG LCD TV (42LC46 - very similar to the 42LC55, uses the same PSU), which I got from the dump. I've looked it up, and the symptoms vary from not turning on (like mine) or intermittent power problems.

Anyway, there are four 2200u 10V caps on the PSU board that go bad. They might not look bad but they can go bad without bulging.

I think what I have highlighted are the right caps; can you post a closer pic of them?

The repair is dead easy, and the caps cost less than £5 (for 9 of them - I kept some as spares and ended up using them to repair a Samsung too.)

[drmore]

Re: Help Needed. LG 42LC55

Thanks for the help. Parts on order. Hopefully my tv will be weorking again soon.

[nick85]

Re: LG 42LC55

Hi not sure if this is the correct way to post for the help I need but here goes.
The problem I have is with my LG 42LC55,
I couldn't turn it on at all there was not even the standby light would come on. After reading up on it online it sounded like the capacitors on the power board so I bought a complete power board from CRADEAL (which I have just realised probably not the best place to buy from) and for some reason board looks slightly different to the one I took out in the first place.

I now have the new power board I bought in the tv but have few other problems:

1 - When I turn the tv on it comes on for a few seconds then goes back to standby.
2 - If I plug the scart lead in from the freesat receiver (which is switched on) then turn tv on it stays on but I have a white line a few inches thick from left to right at the top of the screen then after around 5-10 seconds I see smoke coming from the back of the tv at the top right (looking from behind tv). The smoke looks to be coming from behind the metal that the boards are attached to.

I cannot seem to find out what is wrong now, whether its a bad power board or one of the other boards, can anyone please help me.

[tom66]

Re: LG 42LC55

Hi not sure if this is the correct way to post for the help I need but here goes.
The problem I have is with my LG 42LC55,
I couldn't turn it on at all there was not even the standby light would come on. After reading up on it online it sounded like the capacitors on the power board so I bought a complete power board from CRADEAL (which I have just realised probably not the best place to buy from) and for some reason board looks slightly different to the one I took out in the first place.

I now have the new power board I bought in the tv but have few other problems:

1 - When I turn the tv on it comes on for a few seconds then goes back to standby.
2 - If I plug the scart lead in from the freesat receiver (which is switched on) then turn tv on it stays on but I have a white line a few inches thick from left to right at the top of the screen then after around 5-10 seconds I see smoke coming from the back of the tv at the top right (looking from behind tv). The smoke looks to be coming from behind the metal that the boards are attached to.

I cannot seem to find out what is wrong now, whether its a bad power board or one of the other boards, can anyone please help me.

I think you'd have been better to have repaired your current board. The smoke seems to indicate fried components; maybe the connector pins were different and you've got the wrong voltages on the wrong parts. In which case you could be looking at a new main board and/or new T-con.

[nick85]

Re: Help Needed. LG 42LC55

Wish I'd have sorted original board now would have been cheaper but I'll learn from that. Will check the T-con and main board to see if either are burnt but where would be the best and cheapest place to get these 2 boards in uk if needed? Also the capacitors for the other board? not sure of model numbers I dont want to get crappy ones.
Thanx again.
Nick.

[tom66]

Re: Help Needed. LG 42LC55

Wish I'd have sorted original board now would have been cheaper but I'll learn from that. Will check the T-con and main board to see if either are burnt but where would be the best and cheapest place to get these 2 boards in uk if needed? Also the capacitors for the other board? not sure of model numbers I dont want to get crappy ones.
Thanx again.
Nick.

The smell of burnt components is a lot like burnt plastic. It might not be worth it to replace both boards. If both boards are fried then a new TV may be cheaper. eBay is a good place to source the boards.

I used Rubycon YXF 2200u/10V capacitors. TV is still working 7 months later.

[volvis]

Re: Help Needed. LG 42LC55

I had this problem with my LG LCD TV (42LC46 - very similar to the 42LC55, uses the same PSU), which I got from the dump. I've looked it up, and the symptoms vary from not turning on (like mine) or intermittent power problems.

Anyway, there are four 2200u 10V caps on the PSU board that go bad. They might not look bad but they can go bad without bulging.

I think what I have highlighted are the right caps; can you post a closer pic of them?

The repair is dead easy, and the caps cost less than £5 (for 9 of them - I kept some as spares and ended up using them to repair a Samsung too.)

Many thanks i´ve had the same problem and found 4 2200uF bad caps on my mainboard.
Again thanks for your useful help!