Keyboard not recognized

[witchblade]

I built a computer for a friend of mine, and everything was working fine when I left (isn't that always the case?). Anyway, the keyboard is no longer recognized by the system. I tried a different keyboard, but it didn't work either.
I have not attempted to plug the problematic keyboard into another system yet, but I don't think the keyboard is the issue, being that the keyboard isn't even recognized in the list of hardware.
I've tried turning the computer on without the keyboard, turning it off (let me know when you're dizzy), plugging the keyboard back in, and turning the computer back on, hoping that a new hardware device would be recognized, and I'd be able to run through the hardware wizard, but it's not working.
I fear that there is a problem with the motherboard, but the port for the mouse works fine.
Any ideas on what I can try next?

 

[pbwarrior]

http://www.networktechinc.com/technote.html

is a website with the pinouts of keyboards. You can use that to help check the ps2 connector.

If you have connected and disconnected the keyboard while the computer is powered up it is possible the keyboard port is shot.

 

[edfair]

Keyboard port on M/B. If you can't get into setup, generally the port is bad. But setup may also have a keyboard disconnect setting. So you might want to blow the CMOS settings and then change them to what you need. If the keyboard comes back, then CMOS was the culprit. Can't remember which BIOS had the setting. Ed Fair
efair@atlnet.com

Any advice I give is my best judgement based on my interpretation of the facts you supply.

Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[dakota81]

Another common problem is a blowout of a fuse protecting the circuitry from any high voltage coming in from the keyboard port - caused by unplugging or plugging in the keyboard while the machine is turned on. If you want to give this a shot, locate a fuse next to the keyboard input on the motherboard and short it out. If the keyboard works then that's the cause and go ahead and carefully solder a small wire to permantly short the fuse. Many motherboards don't even have keyboard fuses so you're not really hurting anything. And if you think you'd be uncomfortable doing this, the motherboard is useless without a keyboard anyways.

And obviously, shorting a fuse is like replacing the fuse, just you don't have the same protection from high voltage coming in. Again, many motherboards don't even have this fuse.

I've fixed many motherboards with this type of problem, it's really not that difficult, as long as you are careful with what you do. But if you really don't think you want to do this, then don't, it's only money for a new motherboard.

 

[mmosier]

I am having the same problem and was given the same advice but can't locate fuse. I tinker with electronics but my MB has lots of rectangle numbered black pieces soldered to the board.

 

[blubeast]

Have this problem with older AT type mobo's and usually wind up repairing the keyboard plug in on the board .... lot of hassle but saves on money .... hope the problem is as simple as that ...

 

[edfair]

mmosier,
you'll need to trace the power back from the socket to power supply connector to see whether there is a fuse there. Ed Fair
efair@atlnet.com

Any advice I give is my best judgement based on my interpretation of the facts you supply.

Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[mooby]

is there a pin missing from the connector?its a common problem