I'm sorry to hear that you're having an issue with your set.
Unfortunately, I'm unable to diagnose the television without looking at it. I'd recommend having a technician take a look and give you a diagnosis.
Our TV has been turning itself off and on... got a new lamp several months ago but it still continued to turn off and on. Now various lines -- mainly white ones -- flicker all over the picture and the TV eventually shuts itself off again. The back of the set seems to get hot. I "fixed" it once by unplugging the tv and blowing air into the back of the set, but now that doesn't help at all..... What do I need to have replaced?????? Thanks in advance!