My son is troubleshooting an Apple II plus (actually a complete rebuild and testing of the machine) and finally he's up to doing a memory test and it fails using APtest's 48k memory test. I'd normal use the dealer diagnostics, but it won't boot, an indicator of a low ram issue.
Is there documentation around on this program so we can understand which chip it is? It says ROW D and has Error 4040 before it, but we are not sure how to interpret that other then row D.
I told him he can keep 1/2 the money from selling it, but it must be 100% working and the keyboard must be rebuilt as the first item (which I did have to help him with) so this memory error is all he has left unless he decides to touch up the paint.
Thanks,
Corey
Look at the motherboard - there are letters and numbers going around the perimeter, indicating rows and columns of chips. "Row D" is just that - the row of memory chips that is closest to the "D" marker. Simply swap around two rows of memory chips (there are only three rows of memory total) to move the problem elsewhere in memory.
Well I was trying to avoid having him swap 16 chips but he did and found a bent pin.
Then of course the power supply started smoking while running a continual memory test. Guess its time to recap that one, I'll do that myself won't let a kid do that
Still was a good learning experience for him. He got to use my TTL tester and check every chip and he ESR'd all the electolytic caps on the board. He even tracked down a bad socket and replaced it and put a new video connector in. So he got to use the desoldering station.
BTW this is the same kid who helped build the Mimeo I donated to the MARCH computer group at the InfoAge science center.
Cheers,
Corey