Television and Home Theater

Hello everyone.  I have had my Zenith since 2001. I would like to know if anyone can tell me why the picture is darker and there seems to be a green ark or glow from bottom left corner to bottom right. It used to only do this a few times and snap out of it. I have also noticed that when it is in 16:9 ratio and the whole screen is white even for a couple of seconds it shuts off.  I would like to know what I should look & ask for when contacting a service tech. Any ideas on what and how much this could cost? I also had problems with it turning off and on by itself on start up.

Hi:

I just received a used Sanyo TV model no:
DS25320 with no remote. The TV is stuck on the blue Video screen...I
think I need a remote in order to change the channel - by pressing
"input".  Does anyone here know what I need in terms of a
universal remote?  Will any universal remote work? 

Thanks for your help!!

Hi, I have that plasma for 3 years and suddenly the picture turned green. That is only when I connect a video source. If no source is connected, I have dark screen.
I can see the titles during the dark screen appearing.
Anyone please help...I was a TV technitian and can follow technical instructions.
Thanks!