I have a FDS that I replaced the belt on and now it gives me an error 22. I found a website on how to align the heads so I tried that. Still no luck. Could my disk be bad or is it more likely the drive? here is the site http://jfgoods.net/disksystem.html (http://jfgoods.net/disksystem.html)
You can easily test if it's the disk or the drive by trying another disk.
I don't know anything about the FDS but I'd open it up again, see if there's anything obvious, reseat any bits you messed with, and try again.