Vintage Synth Repair

Hi there,

Short summary: I am looking for a copy of the complete Kurzweil K2500R 
service manual with schematics.  I've seen the one on Scribd (missing 
the schematics) but would like the whole thing if possible.


Longer story:

I have a K2500R which cannot proceed past the "Please wait..." display 
on boot.  Pressing Exit does not appear to invoke the boot loader as it 
should (i.e. nothing visible changes).  I can press 4-5-6 to start the 
button scanner and it appears to works OK (LEDs show which button is 
pressed) but the display does not update in this mode.

I found one discussion which sounded like a similar issue, with 
suggestions that either:
a) the power supply is on the edge of failure and some of the power 
rails are OK but others not, or
b) there was an issue with the main CPU.

The partial service manual on scribd.com (missing the schematics) has 
some test procedures that I will follow, but I'd like to try to find a 
complete copy if possible.

Thank you, denizens of VSR for your help!

Cheers,
A.