LG 50pb690V dead

[jczarniak]

Hi,
TV is not switching on, standby light appears for about 1 second after disconnecting power cable.
Power supply has got Vs and Va present, correct voltages.
Where should I start my troubleshooting, please?
Thank you for any help.

[Hamie]

Re: LG 50pb690V dead

Can you see what the voltages are at z-bias on the z-sustain and -vy and vsc on the y-sus.

This TV generally has a failed y-sustain caused by a shorted surfacemount capacitor.

Post back your results

[jczarniak]

Re: LG 50pb690V dead

Can you see what the voltages are at z-bias on the z-sustain and -vy and vsc on the y-sus.

This TV generally has a failed y-sustain caused by a shorted surfacemount capacitor.

Post back your results

Thanks a lot for your support.
z-bias = 66-67V
vy = 0, cant find test point for vsc on Y-sus board.

I'm just not sure if there is a problem with Y-sus or Z-sus.
With disconnected Y-sus or both (Y-sus and Z-sus) still no signs of life, no standby, no reaction on remote etc...

[Hamie]

Re: LG 50pb690V dead

Your fault is on the y-sustain.
Take a picture of the bottom half of the board.

[Hamie]

Re: LG 50pb690V dead

Out of interest is there a green flashing led on the control board?

[jczarniak]

Re: LG 50pb690V dead

Out of interest is there a green flashing led on the control board?

Led on control board is dead.
See attached pics of y-sus board.
Thank you.

[jczarniak]

Re: LG 50pb690V dead

Your fault is on the y-sustain.
Take a picture of the bottom half of the board.

Done.
See attached in the post above.
Thank you.