fixing am radio?

My uncle had 30 yrs repairing electronics. He always said a good cleaning often cured a non-working electronic piece. Sounds like you want to take it on (good on you) so I'd suggest taking it apart-take a picture. Get as much info as possible on numbers, etc. Google your manufacturer...usually you'll end up getting to some company historian who'll send you some helpful info. Who knows, you might learn so much and like it you start repairing them for others. Start by digging in and giving it a good cleaning.