I spent some time doing some repairs on my Yamaha SY-85, and took a bunch of pictures during the process. If you've ever needed to repair your SY-85 and either couldn't afford to or didn't want to bother with taking it to a service place and paying a lot, I've set up a page detailing how you can get into it and do things like replace fuses and boards, replace broken keys, clean things, etc.
http://www9.50megs.com/theturtle/sy85/sy85a.htmlNot a commercial site, just me and my experiences. I've had mine since late 1992 and still think it's the finest sample synth ever made.
If you have specific questions, feel free to email me... I don't get in here much.
Turtle