68kMLA Classic Interface

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Bad ROM Simm
Posted by: slomacuser on 2023-12-24 08:31:49
Do this ROM fail offten? I had it in Mac IIsi for a while. Tried today after some time and it wont boot only black screen. When removed the IIsi starts fine. The jumper was set as should closed on ROM and open on normal boot.
Posted by: Phipli on 2023-12-24 08:43:41
Do this ROM fail offten? I had it in Mac IIsi for a while. Tried today after some time and it wont boot only black screen. When removed the IIsi starts fine. The jumper was set as should closed on ROM and open on normal boot.
Try spraying contact cleaner into the four sockets. Those sockets can be a bit of a pain.
Posted by: croissantking on 2023-12-24 19:41:26
Do this ROM fail offten? I had it in Mac IIsi for a while. Tried today after some time and it wont boot only black screen. When removed the IIsi starts fine. The jumper was set as should closed on ROM and open on normal boot.
I’d be surprised if one of the flash chips were bad, but it’s possible of course.

It looks like a homemade ROM, maybe there’s a marginal solder joint on one of those PLCC sockets to the PCB. Or maybe one of the chips isn’t making good contact with its socket.

Trying the ROM in a IIx, SE/30, IIcx, IIci would be a good idea if you have any of those.
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