Reoccuring problem with a Panasonic CT-36X41C

[Gnome]

The screen continuously flickers, changes color (whole picture goes
green, or purple), the picture changes sizes for a second or two, and
eventually the tv will  turn itself off. If this happens, I have to
unplug and replug the tv to make it work again, but sometimes the
screen still remains black while the audio is fine. Someone came to
repair this just today, and the problem has already resurfaced within
an hour.
Any explanations as to what could be causing this?




-- 
Gnome