LG 50PA4500 with no display

[jeff52]

Greetings, I am a new member who has a problem with my LG 50PA4500.

When plugged in, there are no lights in front, but one red light on the main board. When I push the on button, the front light blinks red and the stays red but no picture.

In following other thread related to this TV: I have looked at the C802 capacitor and it is not bulging or deformed in any way, I unplugging Y and Z with doesn't affect the front light. There is a hum which is there momentarily when I first plug the TV in and is not there with the Z unplugged.

The voltage on VSTP is 140v and on VATP is 50v. With Z and Y unplugged VSTP changes to 200v and VATP is unchanged.

I am new to TV repair but have done some work on vintage audio.

Any suggestions?

Thanks,
Jeff

[jeff52]

Re: LG 50PA4500 with no display

Well, I looked at it again today and am more confused. I took the VA and VS reading again and they were very low. I pushed the power button and found that they were at 206 and 55 as they should be. This when there is when there is no light on the front panel and the main board shows a red light. I don't know how I got the readings I posted above, I can't duplicate them.

There is never any green light on the front panel. So maybe connecting to power does not reset to the off mode, it powers up in whichever mode it it was in when disconnected from the power.

So, disconnecting either the main board or the Y&Z Sustain boards has no effect on the VA &VS power readings.

Why is there no green light on the front? Is the bulb out, or does this indicate something about the status of something?

Thanks for your help,
Jeff