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32-bit acorn hardware • Re: A5000 battery damage & loose CMOS chip

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Resurrecting this post as I put my A5000 up for sale on eBay last night and this morning I received a message from someone who very kindly informed me that I have the rarer A5000a model!
Yes, it's an Alpha. And frankly even as an Alpha you're asking a hell of an amount for it in that state, IMVHO.

Identifiable chiefly by the "35FC" marking on the ARM3.
Does it look fixable?
That's always difficult to tell from any photo -- you need to get to microscope-level, and start continuity-checking the tracks.

There's clearly a lot of damage around the CMOS RAM, which is missing completely. That's all reasonably readily repairable though - I've done dozens now. But the damage also covers the IDE pins, which can be much more of a problem to fix, and any fix would almost necessarily look a little grotty and be a little fragile just becuase of where the tracks run - often I think it's best to forget the onboard IDE when it's really bad, and just make do with an IDE podule - they can be faster anyway!

Floppy also gets damage, but is somewhat more repairable as many repairs can be done on the underside of the board - there are only a few traces which route near the CMOS RAM / battery damage.

I'd be confident of a "get it running RISC OS again" repair - nominally just the CMOS RAM to fix. You could even do the grim "CJE thing" and use a plug-in CMOS-RAM replacement 'podule'.

Alphas are nice. This one's a 4MB, which is slightly more unusual. But note that the ONLY unique thing about an Alpha is the 33MHz ARM3 chip, vs the stock 25MHz. It has a socketed MEMC, but that's only relevant if you want to 8MB it, and even then it's not a big task to add a socket. In all other respects, the machine's identical to a standard issue 2 board - same PCB, everything.

Statistics: Posted by IanJeffray — Thu Mar 27, 2025 2:52 pm



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