Here is some more disk system repair info:

http://jfgoods.net/disksystem.html

most of the info on the internet just shows how to replace the belt but not how to align the head. I haven't tried any of the procedures from the above website but I have replaced 6 belts and I was only able to get 2 drives working correctly. If I knew how to align the head when I was working on them I may have been able to get them all going. jfgoods also sells replacement belts. I just bought 4 from them.
y-bot