Repairing a Car Radio?

My car radio with digital clock and radio stations tuner has a intermittent problem. When using my radio sometimes the digital tuner lights up and other times it does not. Could there be a short in the radio and is there a way to repair it without taking it to a repair shop or replacing the car radio? Sometimes when it is cool outside the digital tuner works, but when the day is hot it does not come on when the radio is turned on. Any ideas on how to fix this at home without incurring cost?

By Darrel