Panasonic 36" tau model # CT-36S31E... bought in 1999
Comes on easily ,but suddenly goes off as if someone had pulled the plug.
Hitting the remote or power switch does not help @ this stage... you have to disconnect the power cord from the socket ,re-insert it & then hit the remote or power switch... the TV starts... only to go back off 2/5/10 minutes later

Well, first test the outlet just to be 100% sure that is not the cause (although from the sound of it, I doubt it is).

Then if the outlet tests okay, chances are it is the power supply on the TV, but without knowing for certain, you can spend a lot of money on parts. If it were me, I would buy a new TV or use an old one until I can afford a new one.