Re: Help me restore my //c to working order!

["Bill Garber" <willy46pa@comcast.net>]

"Andrew Croney" <abc4e@mtmail.mtsu.edu> wrote in
message news:iqahi6$o2j$1@speranza.aioe.org...
> I recently powered on my //c after a couple months of inactivity, and
> noticed that I couldn't even seem to load ProDOS without the system
> crashing. After a self-test I got RAM errors. I assume a RAM chip has
> gone bad, but I've never had to do any repair on it so I have no idea
> where to begin. There's an error code for the self-test, but it's
> different every time so I don't know how I would determine which chip
> needs replacing. Here's some samples:
> RAM 0 1 1 1 0 0 0 0
> RAM 0 1 1 0 0 1 1 0
> RAM 0 0 1 1 0 0 0 0
> It's summer break and I have plenty of free time, so hopefully I can get
> it up and running and play Oregon Trail again. XD

I'd say that if you are getting a different RAM error each time that it's not
a DRAM itself, but possibly a loose connection on the MMU, Memory
Management Unit, or even the CPU. If these are socketed, you might try
lifting them slightly and pressing them back down to score the pins so
that they make better contact. This is one of the pitfalls of socketed ICs
after they sit around for a time. Let us know how you make out.  :)

Bill