Help, need to fix my 486

[smadavid]

I've got a 486-SX 33 MHz from back in the day. Made by ExpoTech, anyone remember them? Anyway, the AT keyboard controller died on the thing, and I'd love to fix it. I don't know why I even bother, but there's something about it, it was my first computer and I want to keep it going I maxed it out to 32 meg of RAM, added a 2 gig hard drive, ATAPI CD-ROM, worked great! Runs NT4 like a charm, and at a meager 20% CPU utilization to boot, lol. Till the keyboard controller died and I only get "Keyboard failure" at POST, can't get by it. Anyone have experience with this? Do I hafta get out my sodering iron? Is there no hope?

 

[bluemax]

Fixing something imbedded on the motherboard is difficult for a skilled electrician.
Nigh impossible for Average Joe or most computer techs.

Quite honestly, if you can't simply find a replacement motherboard, it's pooched.
Recycle those parts into another 486 or such. If you lived in town I'd give you this IBM/Cyrix 586 processor that runs on a 486 Mobo, but it wouldn't fit in that machine anyways.

Maybe you'll get luck and find one that someone is simply dumping, they're not worth cash (with the exception of high memory and large hard drives.)

Hey, I have to ask...... is that 30 pin memory? You might actually have 2x 16MB 30-pin simms in there! If you do, maybe we can work out a trade! I'd love to add those to a classic sound card!

 

[bendixG15]

I assume you have tried another keyboard to verify that the problem is not the existing keyboard or a
worn loose connection.

 

[DeschutesCore]

A lot of 486 motherboards have removable keyboard controllers. Do you have a large socketed chip (aside from the cpu) locate near the keyboard port? If so, these can easily be replaced if you can find a match. Should be around 1.5" - 2" long.

DC

 

[Buk]

Look closely at the mobo in the vicinity of the keyboard connector for a small fuse - will likely be labeled 'F1' or something like that. It should look like a glass 1/4 w. resistor. Check continuity with a VOM to see if its bad. The mobo components are larger on older boards and not so difficult to replace. I've fixed a couple of older boards by replacing this fuse with one robbed from another board. Good luck......................