Starting on the Amiga 2500
Tags: computer amiga2000 amiga2500 amiga3000 amiga commodore batteries repair
A couple years ago, I traded some car parts to a friend for his dad’s old Amiga A3000 and A2500. I knew that clock batteries were going to be a threat on both of those, so I nobly waited a year to take apart and desolder the battery from the A3000. That was back in 2014.
I only finally put the A3000 back together today, and it seems to be working OK albeit the regular Amiga glitches (both parts keyboards I have barely work/don’t work, the mice are spotty, despite having two Commodore monitors I still don’t have the combination of magic cables/ports that will make them work). The A3000 seems to work well enough to get me into Workbench and let me mess around with the hard drive’s contents thanks to its very nice professional-grade 31kHz video port:
(If you know how to recenter the video output, let me know. I’m guessing the A3000 has a built in flicker fixer or whatever to support 31kHz and needs manual configuration of some kind. I didn’t see anything in Prefs.)
The A3000UX case is in such dire straits (seems to have been dropped/crushed in storage, the 15kHz video port is damaged) that I think I might gut it again later and convert it into an ATX case, but that’s a distant future project.
I’m pretty inexperienced with the platform and was kinda spoiled by my great-running A1200HD which is a fantastic little machine, minus its touchy power supply, and the A500 I got a few years prior to these two that only needed its clock/RAM card removed after the battery exploded.
I started tearing into the A2500 today, immediately after, and found that the battery has popped and spewed gore all over the motherboard. It still seems to boot and do stuff, which is good - hopefully I just need to remove the battery and clean the board and everything will be alright. No combination of monitors and cables that I had lying around let me get a valid signal out of the 15kHz video port, but I also don’t have the composite cables the Commodore monitors want.
As for cleaning the board, I’m probably going to use Deoxit, isopropyl alcohol and a q-tip for starters - will baking soda work to get rid of the battery goo, or will it just make things worse? Hopefully the damage is limited to the surface stuff like these resistors and caps, and I don’t have to try and desolder an entire 68000 socket. I won’t know until I can get the power supply disconnected so I can pull the board to look on its underside.
I feel like an idiot for waiting this long to get around to it, but it probably popped well before I got the machine.
I spent about an hour trying to get the motherboard power connector off with a succession of spudgers and cursing but just ended up with shredded hands before I ran out of time today. I’ll probably throw some more time at it this weekend. Amiga cases are a lot less pleasant to jab your hands into compared to a Mac of the same era - lots more sharp edges and weird cable routings.
The A2500 is pimped out compared to the A3000: it has an AGA-2000 flicker fixer (which I’ll have to make a DE9 -> HD15 cable for), two serial cards for some reason, a SCSI hard card, and some kind of 030 accelerator card with Commodore ROMs on it. The board seems to have a weird warp at the AGA port side, not sure if the previous owner damaged it installing expansion cards or what. If I do have to trash the board, I will hold onto the cards since they are awesome.