Keyboard not functioning from cold boot during POST unless PC is powered off and on again.

[blm999]

The problem revolves around a pre-operating system password set in the BIOS that requires entry before the computer can boot. I have a USB-attached Cherry G80-3000  keyboard, which, upon the initial power-up from cold, all three lights (numlock,capslock and scrolllock) flashes briefly but the keyboard then fails to function. no keys work, (Caps lock/num lock/scroll lock do not turn the indicator lights on)
Consequently, I am unable to input the password.
However, here's where it gets interesting – if I power off the computer using the front button and then power it back on again, the USB keyboard is identified and functions correctly. This workaround allows me to input the password and proceed without any issues. Having to turn the computer on and off then on again just to enter the passwoed is a bit tiresome.
The problem appears to be that from a complete cold boot the BIOS is not communicating with the keyboard propery but on a semi-cold boot the keyboard is identified correcty.
I am guessing that this issue is getting masked from other users because perhaps not everyone has a bios password set before the allowing the boot process to continue. Once the operating system takes over then this would take over control of the usb keyboard and everything would appear to be ok.

This appears to be a bug in the UEFI bios. On my previous PC (HP Z2 G4) it was configured exactly the same but there was no problem.
I have tried all the USB settings in the bios and it makes no difference. The problem only occurs from a complete cold boot (e.g. powered off on the wall left overnight then powered back on).

Hope someone can help

many thanks.

[TheOldMan]

Just FYI: try one of the USB 2.0 ports on the back to see if that makes a difference.  Sometimes the USB 3.0 ports are troublesome on boot up.

[blm999]

Thank you and apologies, I forgot to mention that i've tried all the ports on the back. 

[TheOldMan]

The next step is to make sure nothing else except the keyboard and mouse is plugged in and then see if the symptom happens again.  If it is normal then next step is to add one USB device at a time to see which one is causing the problem.

If there are numerous USB items, you could use a USB hub to isolate all of the USB items, except the keyboard and mouse, and plug in the hub after boot-up.

I had a situation, years ago, that had the same symptom and that is what my solution was.

[blm999 · Accepted solution]

Thanks.

I unplugged everything and tried just the hp supplied keyboard in every usb port and it worked fine.
When i plugged just my Cherry Keyboard in it was the same problem in every usb port.
However when I plugged a USB 3.0. 4 way extender into one of the blue usb sockets and connected my Cherry Keyboard to that it worked fine. Also noticed that by plugging the mouse (wired generic) into the USB 3.0 extender as well that the mouse cursor was visible on the bios password screen and i've never seen that before on this or my last pc. so obviously the mouse hadn't been working either.
So the solution for me was to use a USB 3.0 extender and plug my mouse and keyboard into that and not directly into the pc which is extremely counter intuitive.

[TheOldMan]

Good to hear. Glad it is solved.