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View Full Version : Poor 486: Keyboard error



TheLazy1
July 18th, 2009, 11:55 AM
Looking through a box of junk I found this (http://stason.org/TULARC/pc/motherboards/V/VISION-TECHNOLOGIES-486-VIP486.html) 486 motherboard and decided to power it up.

The memory counts up fine but it always comes up "Keyboard error or no keyboard present".
None of the keyboard's LEDs light up at any point, I read that a fuse could be gone but could not find one _anywhere_ on this board.

Any ideas on what I can try? I wiggled the keyboard plug around and it made no difference, there is 5v at the plug anyway.

Here (http://img166.imageshack.us/gal.php?g=1007865.jpg) are some pictures I took of the board.
Any help would be greatly appreciated :D

Chuck(G)
July 18th, 2009, 12:36 PM
Your photos don't show it, but note that JP1,2,3 9,10,11 are relevant to the keyboard used. You might want to experiment with them.

TheLazy1
July 18th, 2009, 12:42 PM
Your photos don't show it, but note that JP1,2,3 9,10,11 are relevant to the keyboard used. You might want to experiment with them.

It's just a small piece of wire soldered between those, there isn't anything to configure there.
:(

Chuck(G)
July 18th, 2009, 02:13 PM
Well, if you've got 5v at the plug (and I assume that you've verified that the keyboard is working), you may well have a hosed keyboard controller on-board. It looks as if those keyboard jumpers switch between the (missing) 8742 and the one inside the UMC set. (i.e. external/internal).

Are you using a PS/2 keybaord with an adapter or a PC/AT keyboard? Sometimes it makes a difference.

TheLazy1
July 18th, 2009, 02:20 PM
I am using a PS2 adapter but I tried another AT keyboard and it still did not work, unless that keyboard was broken as well.
Would it be worth it to try and obtain that keyboard controller or just toss the board?

[Edit]
I have a keyboard controller I stole off a 286 board that wouldn't POST...

Chuck(G)
July 18th, 2009, 03:00 PM
Well, it might work--it certainly wouldn't hurt to try. Be sure to reset those jumpers for "External" keyboard.

modem7
July 18th, 2009, 08:09 PM
Another possibility: the contacts for the keyboard lock switch.

Unknown_K
July 18th, 2009, 08:50 PM
Make sure that the metal on the face of the keyboard connector (motherboard) is tied to ground on the motherboard. Just because you have 5V doesn't mean that the ground cannot be broken causing no cuircuit. I have seen many boards where the shield connecting to the motherboard had snapped from people rocking the plug in and out causing your problem.