Today i have finished troubleshooting a really stubborn 486 desktop PC.
Always had intermittent issues,losing cmos memory data. Especially when moving it or bumping it. I was testing some 'new' cards in it,including a VLB video card (which works fine) when suddenly the issue worsened.
Started giving me a 1-3 1-3 Phoenix bios message every reboot.
Removed ide controller,as well as all the other addons,changed video card and memory, nothing changed.
Since it has a modded DS1287 , tried another one, with no luck.
I've decided to check the motherboard for loose solder joints, reflowed the keyboard and power pins, no luck.
Then i checked the DS1287 socket and i've found out that some pins were horribly loose. Decided to replace it with a brand new socket.
The PC came back to life, no more errors and the CMOS memory holds after the reboot. All those years of intermittent problems for a stupid socket...
It has a nice Pci/VLB/isa combo motherboard, Expertboard brand. 486 dx2 66, 32 megs of ram, sound Blaster 16, 28.8k modem, 3com LAN,and a 270Mb hard drive. Generic s3 pci card from '96 as video since i have heaps of them.