Hi Everyone,
I recently purchased an Apple IIe Platinum and it arrived in working condition. I was able to power it up, enter a simple BASIC program, start the monitor and dump memory, etc. But not long after, they keyboard stopped working. What happens now is as if a particular key is stuck down and repeating constantly. It overflows the line buffer, prints a "\", beeps, then repeats the whole thing again.
Things I've tried:
Googling...
Reading the couple of posts on here about similar issues (but not the same as mine)
Removed all socketed chips (CPU, CF ROM, MMU, Video ROM, Keyboard ROM, AY3600, the HAL, and 2 74xxx logic ICs around position C11/12), thoroughly cleaned both sides of the board, and re-inserted the chips
Tested the keyboard switches (all of them... ?)
Pressed firmly on a bunch of chips and watched - the AY3600 didn't do much, but pressing the keyboard ROM did seem to change the character being repeated
Re-soldered the pins for the keyboard ROM (which stopped it from changing the repeating character, but didn't fix the problem)
All of the above has been done in-situ, and now with all add-in cards removed and the board on the bench out of the case. No change.
In playing around the other night, I tried removing the AY3600 and noticed that the problem continued. I then removed the keyboard ROM and the problem still continued! To be clear, this is both the AY3600 and keyboard ROM removed from the board, and the problem is still there. ?
I don't really know where to go now. Could this be the IOU? I don't have another one to piggy back, which makes it hard.
I'm thinking about re-soldering all the ICs on the board just in case, but it feels a bit sledgehammer-y. There doesn't appear to be any issues with traces, and there's no corrosion on the board anywhere. The machine boots and displays, and I can reset it and run the self test with a pass result.
It was working fine, and now it's unworking... ? And I just bought a Floppy Emu, although I understand the Booti is the thing to get nowadays?
Any ideas that could help would be hugely appreciated.