Yesterday I turned my Samsung plasma TV on and the screen was VERY dim and it makes it nearly impossible to see the image. I've got no idea why and I can't seem to fix it.
I've turned up all the brightness settings and it doesn't help.

The only thing that Google seems to bring up is to turn the brightness up which doesn't help, so I thought someone on these forums might know.

A real quick Google tells me that this is a fairly common problem with Samsung plasma TVs, and the culprit is usually a bad Y-Sustain and/or Z-Sustain circuit board. The part costs about 150-200 USD, but the articles I saw about this are from 2009-2010, so that may not be good price info any more.

At any rate, it may just be cheaper to replace the whole set with a newer one, especially if it's a few years old. If the TV is still fairly new, though, it may still be under warranty.

I just tried unplugging it again and the picture has returned to normal, even though I tried that yesterday and it didn't work. I'll probably have to end up replacing it soon anyway, because of the issues you mentioned.

Mods can lock this now if they want.

At least you got it limping along for the time being.

I used to have a Samsung that I used to play the 360 on, had it for many years until it started changing inputs constantly by itself. I tried all the DIY fixes suggested on the web but in the end it needed replacement parts and it just wasn't worth it. Turns out it was a common fault with the Samsung and after that I decided not to invest my money with them in the future.