PS2 Keyboard - works on one PC, not on the other

martinlest · 17 Nov 2017

Both PCs run Win7 x64. On one, when I plug in a PS2 keyboard, it works immediately. On the other, it doesn't. I know the PS2 port is OK on that second PC, as a PS2 keyboard works fine in the BIOS (where, I think, PS2 is enabled automatically).

I have seen a suggestion that changing certain registry values should fix this.. but the values are identical in both PCs. There must be some setting that differs between the two PCs that means PS2 works differently in Windows.. anyone know what it might be?

(PS2 showed its worth the other day, when one PC got stuck waking from hibernation - the options, discard or re-use the hibernation data, needed a keyboard input to choose, but all USB had stopped working. Luckily, a spare PS2 keyboard, and of course the fact that my PC had a PS2 port, saved the day!).

Thanks.

mrjimphelps · 17 Nov 2017

Did you power the computer off before connecting the PS/2 keyboard? This is a must.

martinlest · 17 Nov 2017

I rebooted it, yes.

mrjimphelps · 17 Nov 2017

That wasn't what I asked. In order to connect or disconnect a PS/2 keyboard, the computer must be powered down while doing so.

martinlest · 17 Nov 2017

Oh, sorry, you mean totally 'off' - not just in the quasi-off reboot state? On the PC that accepts the PS2 though, I can disconnect and reconnect as often as I like whilst the PC is running; the PS2 keyboard always works. But perhaps that that is because PS2 is already 'enabled'. I'll try connecting the keyboard on the other PC whilst it is off and see if that helps.

Thank you. Will post back ....

samuria · 17 Nov 2017

If you have always used USB then you may not have drivers installed for it does it show in device manager as unknown device? On the working one check what IRQ etc it used and see if that is being used on the other PC by something else

martinlest · 17 Nov 2017

I thought PS2 had native drivers? Whatever, all looks fine in Device Manager, no exclamation marks. Thanks.

Megahertz07 · 17 Nov 2017

Never, ever disconnect or connect a PS2 device with power on. Seen many cases that blew up the hardware.

mrjimphelps · 17 Nov 2017

martinlest said:

Oh, sorry, you mean totally 'off' - not just in the quasi-off reboot state? On the PC that accepts the PS2 though, I can disconnect and reconnect as often as I like whilst the PC is running; the PS2 keyboard always works. But perhaps that that is because PS2 is already 'enabled'. I'll try connecting the keyboard on the other PC whilst it is off and see if that helps.

Thank you. Will post back ....

So far, you have been lucky. I hope you haven't damaged anything by disconnecting and reconnecting the PS/2 keyboard and mouse while the machine is powered up.

martinlest · 17 Nov 2017

OK, thanks for the warning. Since I always use a PS2 keyboard with the 'PS2 OK' PC, I never move the plug. Only done so now when testing. Won't do it again then! I think everything is OK.