Nice and thorough explanation, Gorgonops.
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Re soldering the ram on a 512k
- Thread starter Macintoshguy1984
- Start date
So basically im soldering another ram chip on top of the working ones and pins 2 and 14 are connected to were the chip would be? And do i have to take out the old new ones that i installed earlier to tried to fix them?
Not sure what more I can tell you, I don't know what state you have the board in now. The picture you posted of the one mangled set of IC pads sort of implied you didn't have anything installed, but are you saying you do have chips in those locations partially soldered down? The piggyback idea certainly isn't what you *have* to do, if you're getting some contact in the original locations you could simply anchor the chips (or some sockets) in the damaged locations and try to patch together connectivity with jumpers from the adjacent sockets. It doesn't really matter how you do it as long as what you end up with in the end is two sets of 8 RAM chips that have all their address, control, power, and ground lines connected in parallel and each individual data in/data out line connected to its proper destination. The piggyback idea was just an idea for leveraging the fact that you hadn't destroyed every IC/socket location, just a few, and the piggybacking *might* result in having to run fewer jumpers than the alternative.
Maybe it'd be worth you investigating if you know someone nearby with a bit more experience who would be able to fix it for you. I've told you the same idea like three times in ever-increasing detail and you just come back and ask the same questions, so... I dunno, this might be too tough a problem.
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Could i bump the motherboard down to a 128k, ven if the 3 chips dont work?
No. A 128k requires 16 working RAM chips too. It's this simple: The Motorola 68000-based Macintoshes are 16 bit computers with 16 bit data busses and 16 bit wide RAM. Each chip of the type installed in these machines is *one bit wide*, which means you need sixteen of them in parallel to give you your full 16 bit memory. Three missing chips means you have a memory bank with only 13 functional bits, and that just isn't going to work regardless of how "deep" the bank is.
I did the multimeter thing and at f12 pins 7 and 11 our bad and g11 10 and 15
Is it possible to repair the traces with this?? https://www.amazon.com/CircuitWriter-Precision-Pen-silver-based-grams/dp/B00B88B9KI
Oh yah, i tried to replace the ram with soldering it in the board ( not piggybacking) and it gave me error 0f0008 (I think that's what it said, it was hard to read) What does that mean?
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