Re: Apple II (rev1) instability...HELP!

[Nama <forums6000@mac.com>]

Sorry to resurrect such an old thread.
I am still having big issues with this machine. It's a very early rev 1 board whose serial number is around #12000. It even has the dark green slots like in the later REV 0s (not the super early REV 0 light green ones).
Since I got it it has never been very stable as you can see from the above postings, however it did seem to settle down after a while. Well the Apple II has been in storage for about 2 years and I recently pulled it out as I have moved into a new place with enough room to do hobby stuff again. The flakiness has returned, and worse than ever. Initially the machine wouldn't boot from the CFFA and often came up displaying the random character screen, not sure what I did, but I got it working for a while, then it stopped again. Now I can't get either of my CFFA cards to boot. I have removed all the cards except the Language card and the CFFA card in slot 7. The machine either hangs at the 'APPLE ][' prompt, or crashes into monitor when trying to boot from the CFFA. Very very occasionally it may start the boot process, but crashes soon after. If I put the card in slot 6 I seem to have a little more luck, but not much. In slot 5 the boot process sometimes seem to get a little further but ultimately crashes. I've tried the CFFA is all the slots, and slot 7 seems the most difficult. Slot 1 and 2 display the message "Can't load PRODOS" which is kind of promising I guess.

I have reseated all the IC's multiple times now. with little or no change. and previously (a few years back) in desperation I had swapped in and out IC's from another working II+ motherboard to try to find faulty IC's.

At one point the machine just started showing random characters. so I started to suspect bad sockets. I broke out my continuity meter and after some time I found a pin on the 6502 that didn't seem to be making a good connection. I removed the CPU and carefully spread the legs apart and reinserted it. The random characters screen disappeared and I got The 'Apple ][" prompt again.

Now for the weird bit. The other cards mostly seem to work ok. I'm not 100% sure about this yet as I need to do a little more testing and moving cards around. The Carte Blanche in slot 5, 4, 3 and 2 boots and works fine but does not work in slot 6 or 7. The floppy card in slot 6 works fine. 

Anyway, I'm kinda stumped. I've been messing with this system for about 4 hours (or 4 years if we go way back) and I can't see any pattern that I can lock into.  One thing worth mentioning is as this is an earlier machine the internal motherboard mounting allow for more flex that the later models as it has fewer mounting posts. Maybe this flexing overtime has caused some issues. The board is presently out of the case and sitting flat on my workbench.

Any advice would be greatly appreciated. I would really like to get this Apple II up and running as It'll need to be my workhorse machine now that I sold off many of my other Apple II's.

Philip