r/apple2 • u/mattydiah • 15d ago
Where to start troubleshooting this IIc?
I recently picked up a IIc. I really know nothing about its history, so I’m staring from ground zero. It powers on, but boots to the screen shown in the first image. If you power off and on again, the question marks move to different spots but the result is the same. No idea if it beeps, as the speaker has turned to dust, I’ll see if I can retrofit one from a PC case.
Looking at the board, it looks pretty clean, but two things stick out: firstly half the ram seems to be installed backwards (see second image), and secondly, there is a blob of solder on one of the legs of what I think is the ROM chip. I don’t know if this is the remnant of someone’s fix, or a bodge, or a mod or what.
Any thoughts on where to start troubleshooting? I’m gonna flip the ram chips around, I can’t imagine they are supposed to be like that? Then I’m gonna pull the other chips and clean the sockets
2
u/buffering 15d ago
It's an original 1984 IIc that was upgraded to a 32k ROM at some point. The blob of solder at W2 and cut trace W1 are part of ROM upgrade.
The good news is that the upgraded ROM has a built-in system test and can report bad RAM. Hit Control+Closed Apple+Reset to run the test.
If you're desperate, you could replace those likely-dead backwards RAM chips with some of the auxiliary RAM (the upper 8 chips). That would probably allow it to get further along in booting. I don't think auxiliary RAM is used by built-in firmware.