LG 37lc55 turns on few minutes later screen goes out

[vinceroger69]

Re: LG 37lc55 turns on few minutes later screen goes out

maybe worth taking all the power supply votages (usually marked on psu) then once tv goes black re take all power supply votages too see if any have dropped right out or got less in voltage.

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

How would I take them all and from where? Sorry not done that before

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Any advice guys?

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Do know if this is important but I replaced some of the caps with night uf ratings but same voltage would this cause problems?

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

I've decided to come back and sort this I'm testing main board first ex38425201\13 resistors on r100 is coming back shorted or open not sure on term what else should I check?

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

I took all voltage from the pins and they're all out by around 2volts higher then stated on the board also found few diodes and resisters that aren't working so going to swap them out and see where it gets me

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Replaced the main board inside the TV but still the picture slowly brakes up then goes to black any ideas?

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Thanking voltages of pins they seem to fluctuate a little
12v = 12.2-12.4
3-4v = 3.2-3.7
6v = 6.1-6.5
19v = 18.5
19v =18.3-18.7
These are the same when TV is working as to when its on black

[hienton2]

Re: LG 37lc55 turns on few minutes later screen goes out

Unplug LVDS cable . these voltages are stable?.

With LVDS cable plug in , feel the ics of Tcon with finger , Any hot?

If you already changed tcon . Forget this idea.

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Yeah brand new tcon I'm stumped unless main board I bought was dodgy

[Moreno83]

Re: LG 37lc55 turns on few minutes later screen goes out

You used different uF capacitors? uF must "always" be the same , higher voltage is ok.

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Not problem will revert them back

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Anyone have a layout for this board as can't seem to find one to know which capacitors to change

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

https://youtu.be/oYF9F5ILzVg this is what happens when the TV is turned on, any ideas?

[ozy]

Re: LG 37lc55 turns on few minutes later screen goes out

check the smd caps next to the voltage reg on the main board. and the smd mosfets on the rear of psu

post pics of main board,

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

I'll check the MOSFETs on psu I had a new main board off eBay but same problem persisted unfortunately not sure if it was dodgy board or psu. Will upload photo in morning

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Here's picture

[ozy]

Re: LG 37lc55 turns on few minutes later screen goes out

change the caps I have marked in red, and check the one I marked in brown.
The two red ones cause picture flicker or total lose of picture. I always change these for reliability.

[ReeceyBurger123]

Re: LG 37lc55 turns on few minutes later screen goes out

Just reading this now are you sure this is a 37lc55 because I have one in atm which is a completely different chassis ? Also the one I have is a panel fault what panel does yours use ?

[Blueeyes]

Re: LG 37lc55 turns on few minutes later screen goes out

Yeah positive well its what's stated on model sticker on back and no idea the panel make sorry, doesn't appear to say anywhere.