LG 60PV450-UA Testing Main Board

[weimars]

I've got an LG 60PV450 plasma that I'm diagnosing a no picture problem, but has sound.

INFO:

The voltages are all in spec.
The tv powers on and stays on with sound transmitted.
In a dark room you can see that the screen does have a glow to it.
I have used a jumper on the CTRL board to get test patterns (w/ the LVDS cable disconnected) and the patterns display with no lines and look excellent.

QUESTIONS:

Do I conclude that the CTRL board is fine considering the results of the test pattern?
How do I test the main (input) board to confirm it's the source of the problem?

Thanks!

[tom66]

Re: LG 60PV450-UA Testing Main Board

There is a rare chance the control board is bad, if its input circuit is bad.

The main board is most likely the cause.

Without an oscilloscope you can't test the signals between the main and control to see which could be bad. So you would have to try both.

[weimars]

Re: LG 60PV450-UA Testing Main Board

I tried a replacement control board and it has the same problem with nothing changed. So I've ordered a replacement main board and hopefully that'll solve the problem. I'll update when I give it a go.

[weimars]

Re: LG 60PV450-UA Testing Main Board

UPDATE:

I went ahead and bought a new main board for this tv, since my replacement control board didn't seem to change anything, and it works like a dream! I've had it on during the day now for about 3 days and it has performed flawlessly. I actually think it has a pretty good picture.

Thank you tom66 for your reply and thinking the problem through with me!

[tom66]

Re: LG 60PV450-UA Testing Main Board

Glad to hear! Enjoy your TV.

[jerrmrz]

Re: LG 60PV450-UA Testing Main Board

I have the same tv with no picture but has sound..... first started showing signs of possible burn in on top and bottom of screens but now if black with grey patterns on screen.... unable to get a test signal

[GTech6261]

Re: LG 60PV450-UA Testing Main Board

I have a LG60PV450 with no picture or sound. A service tech says (for an 85$ service call) it is the XMain board but since none can be found, I should just trash it and buy a new TV! It is only 30 years old, I dont mind risking it with a used board if anyone knows how to find one?

[GTech6261]

Re: LG 60PV450-UA Testing Main Board

I meant 3 years old..

[chancleta]

Re: LG 60PV450-UA Testing Main Board

I have a LG60PV450 with no picture or sound. i test the buffer board and it seem to be ok the only thing that i see is the blinking led on the t com board can some body can help me ???