IIc Problems!

[ab616@chebucto.ns.ca (Tony Cianfaglione)]

   A friend has a IIc with a big problem.  If you try to boot a ProDOS 
disk, it renders a "UNABLE TO LOAD PRODOS" message and makes loud 
grinding noises like it does when it formats; on DOS 3.3, it just keeps 
running and never stops.  However, if you start it with no disk in the 
drive and the door open, it renders the "Check Disk Drive" message.

   The disks have been checked and run in 7 other IIc's with no problems 
so I know it's not the disks.  This is the same computer that, a couple 
of months, had the RAM chip error and left '@' symbols on different sopts 
on the screen.  As long as whatever you ran was using only the first 
48 or 64K and the 40-column screen, it seemed to work okay.  Now, for some 
unknown reason, it won't load at all.  I'm not sure what to check next.

Tony