Samsung pn50c450b1dxza

[jdoncouse]

Tv turns on has sound and no picture when turned off you see a quick second where the tv panel shows color like in these pictures

[tw2005]

Re: Samsung pn50c450b1dxza

Could be bad XMAIN.

[jdoncouse]

Re: Samsung pn50c450b1dxza

oh yeah actually its when it turns on.. sorry about that one .. it turns on.. color on pictures show up and then it disappears. but i'll look into xmain

[Glitcher]

Re: Samsung pn50c450b1dxza

Check the Y-buffer for a bad buffer IC. Search on youtube "test buffer board shorts" and its done the same way with almost all buffer boards. Usually if the panel turns on and glows with sparkles for a second itll be a bad buffer IC.

Looking at the top of the screen I could see some horizontal lines of pixels --> these can either be a:

--bad connection to panel (reseat the connections to the buffer board)
--bad buffer IC, (however usually when the IC fails it would have shorts on it. The only time it would cause those horizontal lines its if it has bad solder connections or just fully open circuit (which is extremely rare))
--just a bad panel itself with damage to the connection to the panel (this is unrepairable and usually the most likely case unfortunately)

[tom66]

Re: Samsung pn50c450b1dxza

Check panel very carefully for cracks esp. around the edge there was one on the forum recently doing something similar with a crack in the panel.

[jdoncouse]

Re: Samsung pn50c450b1dxza

from the woman i got it from they said that samsung replaced the panel 2 years ago under warranty and they was watching it yesterday and it just started doing what it is doing i was really figuring it was a board more than panel. i havnt ever touched a plasma before so i didn't know if there was a huge difference in it all..

[tom66]

Re: Samsung pn50c450b1dxza

Picture quality is usually a lot better on a plasma; also you get a bigger screen per $ spent with plasma.
The theory of operation is almost completely different and in general more complex, but repairability is typically better than an LCD.

[jdoncouse]

Re: Samsung pn50c450b1dxza

small update.. got a new xmain just because it was cheapest.. now when i turns on i get a hell of alot more of the pixels when it flashes them. Almost enough to cover the full right of the screen. gonna pull out the buffer board and test that next and buy a new y main since it's pretty cheap too. then just pray lol thanks guys for the help

[jdoncouse]

Re: Samsung pn50c450b1dxza

dicking with it some more i checked the voltages on the sticker and they are all good. I heard a zappy kinda sound when the tv cuts on from the y main board. it's the big yellow thing on it. when the pixels cut out again it stops.. so thinking it's the y main defiantly

[tom66]

Re: Samsung pn50c450b1dxza

Did you check the -Vsc on the Y-main?

[jdoncouse]

Re: Samsung pn50c450b1dxza

yes all of the voltages where right actually.

[jdoncouse]

Re: Samsung pn50c450b1dxza

ok i pulled out the buffer board and did the test and i got a short on the third ic from the top.. would this cause the tv to do everything described?

[Glitcher]

Re: Samsung pn50c450b1dxza

Yes the buffer board would highly be your problem as I described on post #4