I'm trying to resurrect an A3020 which has been stuck in the garage for about 15 years and I'd appreciate any advice you can offer. I fear this is pushing the envelope of my hardware abilities but let's see how it goes...
I tested this before it was put into storage and it did work then. It's a standard A3020 with 2MB RAM, RISC OS 3.11 and a single floppy drive, nothing else.
A couple of months ago I dug it out, cut off the corroded CMOS battery and washed the PCB with white vinegar and deionised water, giving it a gentle scrub with an old toothbrush at the same time. There was a fair amount of bright green gunk on the rear connectors and a certain amount of what looked like rust, although the circuit board itself doesn't look too badly damaged to my inexperienced eye.
After letting it dry off I powered it up without a monitor attached and I did succeed in getting it to a point (probably with a certain amount of holding R and/or DELETE down during power-on) where I could press F12 to get an (invisible) prompt, toggle Caps Lock on and off and press Ctrl-G to make it beep.
Flushed with success I attached an old AKF18 monitor and a mouse and naturally the system then decided it was not going to boot to the desktop any more. Now when I power it on I get a rolling solid red display on the AKF18 and a 32-bit code flashed out on the floppy drive LED and that's that. The flash sequence is SSSS SSSS SSSS SSLS SSSS SSSL SLSS SSSL which I make out to be fault code &00020141. Looking at http://www.retro-kit.co.uk/user/custom/ ... ote225.pdf I interpret that as:
- Self-test due to power-on
- PC-style IO world detected
- Ram control line failure
I have soldered on a 2xAA battery holder and installed 2xNiMH AA rechargeables (pre-charged) in it in the hope of that helping, but it hasn't made any difference. (At least it hasn't made things any worse either...)
Examining the circuit board a bit more closely in the hope of spotting obvious track damage (not that I'm sure I know exactly what it looks like), most of it doesn't seem that bad to me, although the underside of the mouse socket does look quite a mess. I've attached some photos; I have some others and can try to take some more if anyone wants a closer look at any area in particular, but as they're quite big I didn't want to attach too many.
Does anyone have any suggestions? I know it's irrational but it really bugs me that it actually seemed to work briefly before developing this fault...