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

[Osgeld <osgeld@cheesefactory.us>]

On May 10, 9:27 am, "Bill Garber" <willy4...@comcast.net> wrote:
> "Andrew Croney" <ab...@mtmail.mtsu.edu> wrote in
> messagenews: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

I agree remove and re-seat any socketed chips, though there is only a
few in a //c