Post to sci.electronics.repair: there are a lot of very good techs there
that will point you in the correct direction.
Actually, one really ought to start with the "FAQ" for the newsgroup.
Really, it's more like a book that Sam has put together, or a few
books, on the topic of the repair of electronic equipment. The alte
"Electronics Now" liked it so much that they had Sam do the repair
column for the final years of its life.
http://www.repairfaq.org
Michael