Motherboard rejects keystrokes before booting into OS

[kakarukeys]

This is a curious problem that happened to my Asus M4A87TD Evo mobo after editing and saving a bios setting.

The mobo simply rejects any keystrokes before booting into an OS. As a result, i cannot get into BIOS or select any option on the boot menu. I can hear faint beeps from mobo as i press any keys on my USB keyboard. So this is not the case of not being to detect the keyboard (that would have given an error message).

After OS boot starts, the keyboard is perfectly fine.

The setting i changed is to enable USB 3.0. I reset BIOS using jumper. Again same problem with USB or PS/2 keyboard. After retrying for 20 times with different USB ports, the keyboard finally worked (once). I reverted USB 3.0. After reboot, same problem again.

Any clue what else i can try?

May not be related: i added two RAM sticks not long ago, but the keyboard was fine before i changed the BIOS.

 

[cin19]

1) Which OS did you use?

2) Can you use the keyboard/mice with USB2.0 ports?

 

[kakarukeys]

1) Which OS did you use?

2) Can you use the keyboard/mice with USB2.0 ports?

Thank you for your reply. The problem is solved. I post my solution here for the benefits of others.

I removed the extra RAM sticks. For some reason, among the two keyboards I plugged in: USB and PS/2, PS/2 appeared to work.

I got into BIOS and reset everything to defaults, including disabling Asus express gate (a built-in Linux OS in BIOS), splash screen, re-enabling USB-3.0, disabling quick boot.

After a reboot, USB keyboard seemed to work now.

I plugged in the RAM sticks again, and re-enabled quick boot. The keyboards continue to work fine. I then removed the PS/2 keyboard.

FYI, I am running Linux and windows with GRUB.