LG 50PG10 No picture

[tech2014]

I have an LG 50PG10 plasma TV with no picture. The tv turns on and screen comes on for a couple seconds(it is just dark grey), then screen goes black. The front LED stays blue and I get all my voltages including VA and VS. I did the buffer test by removing the top buffer board first, then powered up. The bottom of the screen came on, but with lines on it. I did the same thing with the bottom buffer with top one in, I get top half of screen with lines.

I did test for shorts on both buffers and they are good. I am assuming its the YSUS since the lines are on both top and bottom of screen. I tested the VY and VSC. I measured across the resistor and get -196V for VY and 136V for VSC. The voltages come up for a few seconds then they drop to 0v.

What are typical faults fund on the YSUS?

[tech2014]

Re: LG 50PG10 No picture

OK I found out some more info. I removed both buffer boards and just connected the YSUS and powered up the TV. The VSC and VY voltages both stay and don't drop. I found that when I connect the ribbon cable from the TCON to the YSUS, the VSC and VY voltages come on for a second then quickly drop to 0v.

I narrowed it down to main board. I removed the LVDS connector from TCON to Main Board, powered up the TV and all of my voltages are present and stay. Is it safe to assume the main board is the problem.

[tech2014]

Re: LG 50PG10 No picture

So nobody has any idea??

[ReeceyBurger123]

Re: LG 50PG10 No picture

Yes, I have had it with those boards with failed Bga solder joints. Try heating the board with a hair drier see what happens.

[tech2014]

Re: LG 50PG10 No picture

I do have a hot air soldering station. I will try reflowing and see what happens. Thanks.

[Hamie]

Re: LG 50PG10 No picture

Have you ran test patterns with the main board disconnected?

[tech2014]

Re: LG 50PG10 No picture

I will try that Hamie, thanks.

[tech2014]

Re: LG 50PG10 No picture

I found the AUTO_GEN pins. Do I short these with the power on or connect them then power up.

[ReeceyBurger123]

Re: LG 50PG10 No picture

Yes.

[tech2014]

Re: LG 50PG10 No picture

I did the pattern test and I get nothing. Screen stays dark. I took a pic of what the screen looks like when I first power up the TV. Could this be a panel issue? See pic below.

[Hamie]

Re: LG 50PG10 No picture

Did you disconnect the LVDS cable?

[tech2014]

Re: LG 50PG10 No picture

YES. I actually replaced the TCON board and TV still doesn't have a picture. I have all of my voltages, but the VSC and VY voltages are there for a few seconds then it starts dropping to 0v. I remove the ribbon cable going from the YSUS to TCON and the VSC and VY voltages stay on, as well as VA, VS and p/s voltages. Any idea what would cause this. I don't get anything on the pattern test, so is the YSUS bad and thats why the tv shuts down when connected to the control board? See pics below.

[tech2014]

Re: LG 50PG10 No picture

So nobody wants to chime in here???

[Alastair E]

Re: LG 50PG10 No picture

Gawd--Give 'em a chance--Its only been 2 hours!!

Everyone has lives outside of the internet!