Television and Home Theater

my panasonic television (model # CT-20G21U) turns itself off after using it a short period of time. then with in the following hour or so will turn back on. what causes this? And can I possibly make any tiny repairs myself. to prevent this. with the expertise of a technicians instruction. thank you

I have a RCA 27" TV model #F27664. I took it in for repair for a $25 estimate fee. The service guy told me it was the IC and the eeprom was bad. The tv was not turning on. We wanted another $85 to repair. It appears I can pickup the part #244878 for only $7.00 and part # 223653 for only $2.00. I decided not let let the guy fix it sonce I could buy new for only another $50. Does anyone know if it is difficult to replace these parts on my own? I could not find a picture of these parts to judge the difficulty on my own.

Does anyone know how to adjust the vertical hold on a mitsubishi cs-2655R