Lg 60pg3000

[finntricky]

hi, i think i know what my problem is, but just like an experts say on the matter.
so i have 2 questions.
the tv turns on with sound but no pic,so im saying y-sus and buffers,
but, the screen is showing sparkles of red pixels,
also there are 4 LED lights on the T-CON board, 3 are lit out of the 4, does anybody know if they indicate what the problem is ?
thanks for your help
mick

[tom66]

Re: Lg 60pg3000

The LEDs on the control board indicate the panel temperature, 3/4 lit is OK.
Red sparkles can be a number of things - bad Y-sus but also a failure of the control board or main board.
Have you tried jumpering the EXT AUTO GEN points on the control board?

[finntricky]

Re: Lg 60pg3000

not as yet tom, the tv is all back together now, i'll have a look tomorrow and see if i can find the jump points, and get back to you.
thanks,

[finntricky]

Re: Lg 60pg3000

The LEDs on the control board indicate the panel temperature, 3/4 lit is OK.
Red sparkles can be a number of things - bad Y-sus but also a failure of the control board or main board.
Have you tried jumpering the EXT AUTO GEN points on the control board?

I'm posting a pic of board, as I can't find the points,
Maybe you can point them out for me please.
And do i just link the 2 points with a wire?

[tom66]

Re: Lg 60pg3000

The two points just below VS_DA point, I think marked AUTO GEN, bottom right of board.
You also need to unplug top most connector going to main board - the LVDS cable.

[finntricky]

Re: Lg 60pg3000

The two points just below VS_DA point, I think marked AUTO GEN, bottom right of board.
You also need to unplug top most connector going to main board - the LVDS cable.

ok, found it, crossed the 2 points, and the screen still shows red pixel sparkling,
nothing else seems to happen

[tom66]

Re: Lg 60pg3000

OK next locate Vsc and -Vy voltages on the Y-sus board and check them. About 140V and -200V respectively. Leave the ext auto gen jumpers in place.

[finntricky]

Re: Lg 60pg3000

Cant find Vsc found vy and voltage fluctuates from 130 upto 180 volts

[tom66]

Re: Lg 60pg3000

OK, pull out the buffer boards and repeat the test.

[finntricky]

Re: Lg 60pg3000

Now 186 volts drops to 182 then up to 186 again.
Now have blue & green pixels in top right & top left corners with a scattering of blue pixels over the rest of screen.

[tom66]

Re: Lg 60pg3000

Good, try with just lower or upper buffer. The fault is with one of the buffer boards. I fixed a 42PG3000 with the same fault.

[finntricky]

Re: Lg 60pg3000

This is what i have now with buffer disconnected, this image flashes 4 to 5 times then screen goes black for 10 seconds then repeats flashing image again.

[tom66]

Re: Lg 60pg3000

Which buffer out? Odd image given one removed...

[finntricky]

Re: Lg 60pg3000

That was with 2 buffers disconnected,
when bottom disconnected same image on bottom half of screen only, the top half is black with red sparkling pixels as original with all connected.

[tom66]

Re: Lg 60pg3000

I am surprised you can get an image like that with both buffers out, did you completely unplug them from Y-sus? They are screwed in I think, so you need to undo the screws too, as they carry drive current.

[finntricky]

Re: Lg 60pg3000

Ok, will try that, i did not unscrew them will try that now.


When both buffer disconnected just black screen, not lit up.

When top buffer connected top half of screen lit up with red sparkling pixels.

When all buffer boards reconnected and now removed jumper from tcon board,
screen lights up no pixels are displayed, just a black screen.

[tom66]

Re: Lg 60pg3000

In all cases please also check -Vy voltage.

[finntricky]

Re: Lg 60pg3000

In all cases please also check -Vy voltage.

never got a chance to test tonight, so will have another go tomorrow,
but not sure if im testing the correct way or not,
do i just test the 2 -vy points with tester or use chassie for neg, and test positive on both points on -vy.
depends on how i test as to what the volts read.
and also the buffers, you can only disconect both or the bottom, as the bottom buffer runs from conections from the top buffer.

[tom66]

Re: Lg 60pg3000

Try with both out or only bottom in, that is OK for now.
For -Vy test across the resistor marked.

[finntricky]

Re: Lg 60pg3000

ok, tested across -vy and got no stable voltages with 1 or 2 buffers removed,
seems like regaurdless of how many boards are connected to the y-sus the voltages do the same thing,
only time i get anyware near stable is if i remove LDVS CABLE or AUTO GEN, so there is no output from a/v board or t-con, and just get black screen.
im thinking bad t-con now.