Hey, if you're wanting to REALLY "learn" electronic repair go to:
http://www.renovatedradios.com/nri_1927-30.html and get an NATIONAL RADIO Institute complete course on CD for around $20.00. I myself participated in that course (then by mail) when I was just a kid. You don't have to go to Notre Dame "GALVIN' college to learn!!>> in case you're unaware that's where the Motorola guy got a wing named after him.