Television and Home Theater

I have a Panasonic tv which is about 7 years old and when I turned it on today there is a round globe of color.  Does anyone know what might be causing this and could it be an inexpensive repair or should I just replace it all together.

 Thanks for your time.

 Sincerely,

Judy

So I have this Sony Trinitron that worked great.  I recently moved.  Loaded it in a van, moved it to my new house, plugged it in and turned it on.  I comes on for about 3 seconds, the little red timer light flashes 3 times, and then the tv shuts off.  It doesnt even have time to warm up enough to show a picture. 

Any suggestions?  Is there a way to turn off the timer?  The manual doesn't mention anything about this problem.  I would hate to spend more money to take it to a repair shop on the account of an incorrect setting.

I have a Maxent 42" EDTV that started getting bright blue static interference 14 months after purchase, soon after the warranty ran out. It has a direct coaxial cable input and a DVD/VCR combo connected through composite video. I tested the dvd playback to see that both the cable and dvd signal is affected before calling a Best Buy tech to come out and look at it. He hooked up a different dvd player to test and decreed that my signal board is malfunctioning and needs to be replaced.