Where do I begin?

[NiteSpore at aol.com]

I have a SCI Prophet-600 which has died.  It powers up ok and I'm able to
change patch numbers with the keypad, but _all_ of the pots & switches
usually do nothing when I attempt to edit a patch and when I press the keys,
all I get are godawful electronic screeches and drones (perfect for Vangelis
Beauborg or some early T-Dream emulations, but that's not what I _always_
want to use it for!).  I'd like to fix it myself if I can to save a possibly
huge repair bill, but I don't know where to start.  

What tools do I need?

Where do I get parts?  I'd like to at least replace the keyboard but it's got
other trouble more serious than a worn-out set of keys!

How do I get technical info?  Is there a good source of such info that would
be accessible to the electronics layperson?

Would it be cheaper in the long run to just bite the bullet and get the thing
repaired at a shop?  If so, can anyone recommend a reputable shop for SCI
repairs in northern CA?  

It's been in for repairs numerous times, a couple times to the factory under
warranty (a long time ago!), and a couple times to a repair shop here in
Sacramento that is now closed.  I wouldn't take it back to them anyway
because of some of the stupid things they did (I had to take it back at least
twice to fix a grounding problem that they caused trying to fix something
else).

Would I be better off just learning how to build a new beastie from scratch?
 If I do it this way, what's the cost in hours and dollars for someone who's
starting off with minimal prior experience?

If there's a FAQ that answers these questions, kindly point me in its
direction.

If there's another list or a newsgroup where these questions would be more
appropriate, please let me know.

If you respond via email, please do it via the first address below.  I won't
be on AOL much longer.

TIA,
David L. Simpson
david.simpson at sacpcug.org
nitespore at aol.com