p50hdtv10a Plasma snow and lines good sound

[ntehicks]

I have a p50hdtv10a vizio plasma tv that my neighbor brought over to see if I could figure out what is wrong with it. I am not sure where to start. so I thought I would test the upper and lower buffers to see if any of them are shorted. I will add a picture of what the screen looks like

[ntehicks]

Re: p50hdtv10a Plasma snow and lines good sound

I tested the buffers as Coppell tv has posted the upper buffer is 395 and the other direction is infinate. the lower buffer is 76 and 59 which I would think is bad. can I replace the bottom one or do I need to check the y board for problems.

[capkid]

Re: p50hdtv10a Plasma snow and lines good sound

I'd verify that you're getting the proper voltages from the Y-Sus just as a sanity check, but it sounds like your lower buffer is bad. What is the part number of the buffer? The reason I ask about the part number is that it could be that one of the buffer's mosfets has failed, in which case you could just replace the mosfet.

[ntehicks]

Re: p50hdtv10a Plasma snow and lines good sound

the part number on the board is 6870QDC105A
it is a LGE PDP 050805
Board YDRV_BTM
model 50X3

[capkid]

Re: p50hdtv10a Plasma snow and lines good sound

Ok, yes, you've probably seen Coppell's blog, and they mention that a FET on the buffer could be causing your issue. Have you tested any of the FETs? I had an LG-based TV with an identical chassis, and the lower buffer had a bad FET that caused vertical lines on the screen. Also, closely visually scan your buffer chips for pin-sized holes.

http://blog.coppelltvrepair.com/2010...-lines-in.html

Edit: If you choose to just replace the buffer, it looks like there's a substitute if you can't find the original at a decent price: http://www.shopjimmy.com/lg-6871qdh089a-ydrvbt.htm

[ntehicks]

Re: p50hdtv10a Plasma snow and lines good sound

I tested the FET's on the bottom buffer part number FQB46N15 and they were testing bad. I removed all three of them off of the board and tested. just one is testing bad. I purchased a set of 3 FET's and replaced all three of them. the board tests good now. I installed the buffer and now the tv works perfect. thanks so much for your help.

[capkid]

Re: p50hdtv10a Plasma snow and lines good sound

Good to hear.

[ntehicks]

Re: p50hdtv10a Plasma snow and lines good sound

I ran the tv for an hour and figured it was all fixed. now the tv is blanking out. could this be a voltage issue.

[tom66]

Re: p50hdtv10a Plasma snow and lines good sound

When it blanks out, can you still see a glow from the screen or does it go black completely?

[ntehicks]

Re: p50hdtv10a Plasma snow and lines good sound

it goes completely black

[tom66]

Re: p50hdtv10a Plasma snow and lines good sound

OK, check the Vs voltage coming out of the power supply before and after it goes blank.

[ntehicks]

Re: p50hdtv10a Plasma snow and lines good sound

so during the day the tv would flash on and off and now the tv won't turn on at all. I will go and check the VS voltage as well as the others.