Re: Samsung 50" plasma pn50b450b1d has poor white images after 2 hours, turns off aft

I just took the back of the TV off, and checked all the voltages after the TV warmed up, and sure enough, Vs drops from 209 (spec) to 197.

I'm assuming that since the Vs test point is on the power supply board, that the problem lies there.

What could cause this? What can I do to fix it? Should I just trace Vs back from the test point to try to find some component that might be bad? Since this is clearly a thermal issue, could it be that one of the transistors mounted...

As the title says, when I keep my TV on for longer than a couple hours, the whites turn somewhat grey, and high contrast borders, such as black text on a white background, have a white halo. The white halo is the correct brightness, but only located at the border. After the TV has been on substantially longer, between 4-6 hours, it will turn itself off for a minute, then turn back on for 5 more, then off again. It does this until I turn it off and let it cool down.

I've also noticed that if the image only has a small amount of white in it, like if I were using it as a computer monitor...

Re: Samsung 50" plasma pn50b450b1d has colored static on startup, bad white images

Nvm, found it

Re: Samsung 50" plasma pn50b450b1d has colored static on startup, bad white images

Vs and Va are both in spec, but Vsc is 193v, and I can't find a number for what Vsc should be. I have a feeling that this isnt right

Re: Samsung 50" plasma pn50b450b1d has colored static on startup, bad white images

What should those voltages be? If they're out of spec, how can I adjust them? Do I need to recap the power supply, or is there some potentiometer I can turn?

I've been having trouble with a TV I bought in a pawn shop.

When I turn the TV on after it's been off for a while, there is a lot of colored static. This static is mostly red, and seems to be individual pixel flashing. It also occurs mostly in the right side of the screen. This static goes away after a couple of minutes.

Something else that's incredibly annoying is that when viewing a mostly white image, such as when using the TV as a computer monitor surfing the internet, or even watching a movie or playing a video game with a lot of white (in a snowy field, for example),...

Re: Samsung 50 inch plasma has analog noise even with no input signal

I took a picture of the "no signal" screen, to show you the analog noise I'm talking about, as well as a picture of the jumpered pins on the control board. The noise is very slight, the colors are all right, but they're just slightly fuzzy

The test patterns went across the screen, but the noise was still there. I noticed that the tone of buzzing from the x-main board changed, it got quieter or louder and higher or lower depending on the color that was being displayed.

I'm...

This week I bought a Samsung Plasma TV, model number PN50B450B1D, for pretty cheap in a pawn shop. It was cheap because it had an issue where the image looked a little staticy all the time, even if there was no input source selected. The tag said that it didn't turn on immediately, and would shut off after 6 hours. This tells me the issue is thermal.

My background is in electrical engineering, and since this digital TV had analog noise all the time, I figured it was a bad capacitor. I jumped at the opportunity to have an easily fixable big tv for cheap.

I brought...

Re: New Members - please post your introductions here

I'm an electrical engineer, posting a message so I can start a new thread. I've got a 50 inch samsung plasma tv that turns on fine, but has what looks like a little bit of noise in the image, as if the input signal were bad.