Apple IIGS repair - boots to error code

[zinco]

Hello! This summer, I happened across a nearly complete Apple IIGS suite of hardware at a yard sale. On taking it home, I found (unsurprisingly) that the battery inside the computer had burst, causing corrosion damage. I'm not confident in my repair skills, so I brought the machine to a local computer repair person, who removed corrosion where he could and replaced some components (including the PSU, also damaged by corrosion). He has not replaced the battery, as our understanding is that it's not required for the machine to operate outside of the clock.

The computer can now boot, but to an error code.

My repair person is not an expert on vintage Apple hardware or its error codes. He understands that this code pertains to the SCC chip that keyboards and other devices interface with over serial, and speculates that this might mean the SCC chip and/or a crystal will need to be replaced (both of these components also had some corrosion). But at this point, he doesn't feel confident that making these replacements would do the trick, and suggested that I find someone who could have better insight into the problem.

Here's a picture of the board, if that helps. If you need a better picture of a certain area, I might have one available, or I can ask my repairman to take one as the machine is still in his care.

Thank you!

 

[ClassicHasClass]

Actually, error 06xxxxxx can be one of two things: it can be indeed the serial I/O, but it can also be the clock. You would not be able to distinguish the two with this screen alone. Are you able to boot the system after this message?

The SCC and keyboard GLU are on the other side of the board from where your battery bomb went off, so I tend to suspect the clock/calendar chip.

 

[zinco]

From what my repairman tells me, this error code is as far as the computer goes when booting.

Part of the reason he suspects the SCC chip is because that's one of the areas where he had to remove corrosion, in this case from the solder.

I can imagine it being the clock chip from what you tell me, although looking at a closer picture of the area, the chip itself doesn't look like it's been affected, but I would potentially worry about the traces.

With the amount of rust everywhere, I wouldn't be surprised if, along with the battery bursting, this unit was stored in fairly poor conditions...