Bill Garber wrote:
"Michael J. Mahon" <mjmahon@aol.com> wrote in message 20040414152114.17367.00000399@mb-m16.aol.com">news:20040414152114.17367.00000399@mb-m16.aol.com... : Bill Garber wrote: : : >It could be that the RAM expansion cards pins has : >deformed the sockets in which the CPU and MMU have : >to return to. What you can do is replace the sockets : >one at a time in the motherboard, if you have the skills, : >and see if this remedies the situation. : : I agree that deformation of the sockets is the most likely cause. : : If you'd like to avoid the tricky desoldering job, though, you can : simply "piggyback" your CPU and IOU chips on two 40-pin : machined pin sockets, which will plug securely into the : main board sockets. : : You must use _machined pin_ sockets for this to work. : They cost a little more (a buck or two) but this is a much : safer repair than desoldering unless you have special tools : and some experience.
The suggestions about the deformation of the motherboard's sockets makes sense. I remember that when I reinstalled the CPU and MMU, they just sort of slid in a bit too easily.
I went back and removed those two chips for a closer examination. The first thing I noticed was the amount of tarnish on all the legs. I used the old ink eraser trick to remove the crud. Then, I carefully bent the legs out slightly all the way down both chips (straightening out a couple on the end that weren't exactly straight). When I reinserted both after these actions, they both "clicked" in, taking only slightly more pressure to seat. After closely looking around and not seeing any bent or broken pins, I closed up the case.
The Apple //c has now been running for seven hours straight with no crashing! :)
He may also have to remove the keyboard brace for thisto be effective as well.
I didn't notice any keyboard brace installed on my //c. Perhaps you're thinking of the //c+?
it has also been suggested that a memory chip is going bad. That can be checked with the internal diagnostic. I have the chart that tells which chip it is if there is a bad one. Run the diag numerous times, I'd say at least 20, to be sure it passes.
I ran the self-test a number of times before I performed my erasure. Each time the response was "System OK". I suppose I could have used other utilities to run checks, but I don't have any on hand.
Unless, of course, there's one or two contained within this cache of "Software of the Month" disks I've got. Now that my //c appears to be working, I'll be taking a stroll through those...
:) Thanks to all who offered assistance. It was appreciated. Regards, Steve Adams