Sign in with
Sign up | Sign in
Your question

Old Keyboard Not Working

Last response: in Windows Vista
March 27, 2010 8:55:47 AM

Hi all, I want to think that this is a software related issue, but I know that keyboard issues can be a motherboard problem. I ended up fixing a friend's computer tonight, she uses a PS/2 style connection keyboard. She just brought her tower to my place and I plugged in my USB keyboard, fixed her computer (nasty WORLDWIDESOFT BAKU scam), and gave the tower back to her. Now her PS/2 style keyboard isn't working. Any ideas? I've tried searching these forums and all I'm getting is that PS/2 isn't plug and play while USB is, but I'm not sure what to do (other than give her my nice keyboard :p ).

More about : keyboard working

a b \ Driver
March 27, 2010 9:15:33 AM

all I'm getting is that PS/2 isn't plug and play while USB is

What ths means is you can not unplug/plug in the PS/2 keyboard while the machine is on or damage may occur. A USB keyboard is hot swappable and can be unplugged or plugged in while the system is running.


PS/2 ports are designed to connect the digital I/O lines of the microcontroller in the external device directly to the digital lines of the microcontroller on the motherboard. They are not designed to be hot swappable. Hot swapping PS/2 devices usually does not cause damage due to the fact that more modern microcontrollers tend to have more robust I/O lines built into them which are harder to damage than those of older controllers; however, hot swapping can still potentially cause damage on older machines, or machines with less robust port implementations.

If they are hotswapped, the devices must be similar enough that the driver running on the host system recognizes, and can be used with, the new device. Otherwise, the new device will not function properly. While this is seldom an issue with standard keyboard devices, the host system rarely recognizes the new device attached to the PS/2 mouse port. In practice most keyboards can be hotswapped but this should be avoided.
March 27, 2010 9:45:10 AM

I guess I didn't mention that, all of the keyboard swaps were done when the system was off. But I did learn something, so thanks!
Related resources
a b \ Driver
March 27, 2010 9:46:43 AM

Check the pins on the PS/2 connector. One may have gotten bent.
March 27, 2010 4:03:15 PM

The pins appear to be OK. Something she didn't tell me right away was that she was on her computer after I had given it back to her, the keyboard was working fine, and then she went to restart it, and then her keyboard stopped working.
a b \ Driver
March 27, 2010 4:24:03 PM

I suppose some phyical damage is possible, not sure. I had a kid jerk his PS/2 mouse out and corrupt the system registry. The system would not load as a result. It's been a while back, but I believe the bootloader was corrupted and perhaps other OS functions. So, if you plug in the PS/2 keyboard and check 'device manager' and the keyboard does not show up there, I would say physical damage is possible or the OS has been corrupted. Maybe consider doing a 'repair install' of the OS or a clean install possibly. With Vista, you can boot to the Vista installation disk and go to the repair my computer link. Run that repair function and see if any OS system files are repaired there. I'm not entirely certain, but perhaps it is worth a shot.

EDIT. Will any other PS/2 keyboard work properly on the system?