LG 42 LK 450N won't start

[Andrew F. Ali]

Re: LG 42 LK 450N won't start

Post pics of the PSU Bd and the back of the TV.
Are you getting StdBy 5V when you plug into the AC without trying to turn it on?

[manoftheyear]

Re: LG 42 LK 450N won't start

Anyone? Where to start, which board to suspect? A little 'tick' kind of sound can be heard I believe from the PSU each time the voltages drops and raises.

[manoftheyear]

Hello

TV goes on and blue led lights on for 5 seconds, then the tv switches off and red led comes. Screen stays black all the time.

something wrong with the power supply voltages, when the TV is on for 5 seconds my DMM shows P. Dim runs between 0v and 3.1v, A. Dim somewhere between 1.7 and 3.1v, INV_ON and Error out rails go from 0v to 3.4v.

Can the inverter and the backlights be checked by jump wiring? I tried a jump wire (680 ohm resistor between) from the 3.5v rail to INV_ON and PWR_ON. Nothing happens. By doing this the main filter cap has only 330v (line is 230AC), PFC not working this way?

Service manual here https://cdn.badcaps-static.com/pdfs/...b64fd020f0.pdf

Not the exact same but many similarities and mostly same components.