LGLP2637 Low 3.4v

[Turnip]

Hi folks,

Have a couple of these in where the 3.4 supply is low at 1.5v'ish although other S/by supplies are OK.   

Note the P/S is a bit complex with some s/m power fets thrown in here and there, and I can't work out where the 3.4v comes from - have replaced all likely caps.

Anyone with ideas or a shematic (manuals seem to fight shy of P/S info)

Many thanks - Chris.

[sparky]

hi chris
try sending tony the lg wizard a pm
dave

[zica]

Had same problem with a 37" LG.
3,4V needed on-signal from mainboard to activate a pwm ic on p/s.
Without the on-signal from mainboard i had only 1.09V

[t1412]

hi turnip, don't know if this will help, had a lg in today 32inch stuck in standby, 12v was showing 3 volt traced it to 3 capacitors 1000mf 10v hope it helps

regards
shaun

[Turnip]

Hi folks, and thanks.

Fortunately I got spare PS boards from Fleabay that worked OK, so that the (ever 3.4v) prob is def on the Power boards, and having two the same, must be quite common.

Should have checked the good boards to source that (ever 3.4v) but custs were pressing.

Thanks again - Chris.