Sony KF-50XBR800 Turns on and off.

[paache]

Iam servicing a Sony KF-50XBR800. When the set is turned on it will come on perfectly but aftef about three to four minuites it will turn off. the stand by light blinks constantly the same as when the set is first turned on and then the set comes back on, it will continue to do this untill the set is turned off.The light does not blink in any sequence. The self diagonistic screen only shows that the set had 1 problem. 4: Temp. Any help would be appreciated.

paache