need major help with my 36a50?

Problem with my toshiba 36A50?

I have a toshiba36A50. I was watching the TV the other day and everything was fine. Then the screen turned into a dot for a second. then it came back. then it went to a dot and went out completely. Now if I try to turn it on. It sounds like it is going to turn on. Then doesn't and the power light dims in brightness a bit and it stay like that. I was told this is the power supply going out, but what components make up the power supply if that is the problem.

thanks.

ray