L.G.32LC56-ZC. PICTURE GOES OFF AFTER A FEW HOURS.

[maff99]

Hi guy's,got one of the above,which I had in back in oct last year for dead set stuck in stby.replaced secondary caps all o.k. But now the picture goes off after a few hours then shuts down to standby.The back lights go off then it shuts down.no amount of heating or cooling seems to effect it.But if you leave it off for a few hours away it goes working o.k.Anybody had any prob's like this with L.G.A new p.s.u.inverter p.c.b. for one of these is about £90.So don't want to gamble if it's a back light prob.
any ideas? many thanks Maff. The p.c.b. is marked L74SK347950010120 or EAX32268501/9.
CHEERS MAFF.

[maff99]

Hi guy's.T.V.Tony,may not know it but he is a star!Found an old post reguarding same set but dead.T.V.Tony posted a mod sheet that covers numerous faults with this chassis.I carried out the mods & so far so good,fingers cross.Many thanks Maff.

[Mjolinor]

Hi guy's.T.V.Tony,may not know it but he is a star!Found an old post reguarding same set but dead.T.V.Tony posted a mod sheet that covers numerous faults with this chassis.I carried out the mods & so far so good,fingers cross.Many thanks Maff.

Can someone give me a link to these mods. This is mentioned in a few posts but I can't find the post that is referred to.

I have a 32lc56 that goes off after warm up (approx 15 minutes from cold). Removing power for a while gets it back for a while. the 3.4 volt rail disappears when the thing goes off but I don't see any problems with the PSU. There is a signal marked "3.4 on", this starts at about 0.9 volts at power on and falls slowly, when that gets to 0.67 volts the tv goes off. I put a pull up on it and it will stay on much longer but still after a few hours it will lose DTV and audio. I can probably make it stay on by using a smaller pull up or a higher feed voltage but it isn't really a fix, I would like to know where the original fault is.

[Mjolinor]

Typically and in line with the fundamental laws of the universe I found it immediately after posting, isn't that always the way.

http://www.tv.quuq.org/forum/index.php?action=dlattach;topic=1714.0;attach=1251

For the next guy that tries to find it.

[Mjolinor]

I have applied the mods as dictated in the PDF. This has made no difference, the "3.4 on" voltage still falls slowly and the set goes off at 0.670 volts.

Anyone any input please.

[Turnip]

Hi Mjoliner,

Found this on my list for the set - may be useful

Switches to S/by after 20 mins – usually restarts and runs for a shorter period. Just B4 tripping backlight goes out. Thoughts are that it’s an invertor problem as heating invertor transformer T701(2130KP0175A-F) provokes the problem.

Had invertor tranny problem where dries caused a burn-up.  All the best - Chris.