I have a gigabyte z87x-ud5h that had been working fine for years, until today. I moved the computer to a different room and when I tried booting it up again, the BIOS had reset and it would not respond to any inputs mouse or keyboard, ps/2 or usb. It’s stuck on the BIOS has been reset - choose how to proceed, but I can’t as no input device is recognized. USB devices are showing no signs of receiving any power and ps/2 appears to get power, but still no input is recognized. I’ve try clearing the cmos, stripping it down to just the cpu and 1 stick of ram, but still nothing. I’ve tried the usb 2 ports and usb 3, IO panel usb and MoBo header usb, multiple keyboards. Nothing works.
The rest of the major components are an i7 4770, 4x 4GB DDR3 12800 modules, msi gtx 1070 and corsair TX550 psu.
its not the psu, i took out the graphics card, disconnected the drives and tried it with a known good 450W Dell server psu to the same result. It makes it to the BIOS has been reset screen and waits for user input, but no mouse or keyboard works.
It appears as if the board is perfectly fine otherwise.
Welp, looks like it might be the motherboard/BIOS then. Be careful with that PSU in any case, it may have had a role in the motherboard’s demise. I bought a non-booting threadripper mb/cpu combo off ebay and narrowed the problem to the CPU by swapping components, which AMD replaced for no charge. In that case the MB was stuck in a boot loop right after boot, displaying 3 bios diag codes in a row over and over again. In another case I “upgraded” the BIOS of an Intel engineering sample motherboard to the most recent release. No dice, BIOS did not work and motherboard had a similar boot loop, CPU and memory worked but mb gave me the spite.
its a possibility the mobo is shot
its not the first time Ive seen something like this
Ive had it happen once the keyboard tested fine on another system and when trying a new keyboard the same result.
different things can cause the ps2 port to fail and its generally not good!
at work Ive seen it happen when the bosses unplugged the ps2 keyboards and mice without shutting down…
(old rule psu!!! shutdown!!!)
some of todays boards may have some protection against disconnect surge but its still best to follow the old rule!
during bios boot a legacy usb keyboard may work at initializing during post but may be disabled during post until bios boot has been completed.
if your bios is set to ignore keyboard errors it will boot the rest of the way through bios.
and may let a usb keyboard work or it may not.
that depends on the mobo.