Question Stuck at BIOS boot. Keyboard doesn't work

[Gecko05]

Hi, I got this PC that stopped working due to no apparent reason. Used the PC at night then the next day when I came back from work it wasn't working anymore. I'm not sure if the MOBO is broken or if it is the processor. When I turn it on it sometimes gets stuck after the Gigabyte splash screen and then resets or it just gets stuck after loading the BIOS with the "Verifying DMI pool data..." message. I tried booting up with a Linux pendrive but it cannot even do that and when I go to any BIOS option menu like boot devices and such, it stops responding to my keyboard almost immediatly.
I already tried resetting the CMOS by removing the coin battery for around 20 min.

Setup is:
Gigabyte ga 78lmt usb3
GTX 750 ti
8 GB RAM DDR3

 

[Darkbreeze]

Have you tried DISCONNECTING all attached devices except the keyboard and mouse?

So, other than the keyboard and mouse, and with the system shut down and power unplugged from either the PSU or the wall, unplug any printers, disconnect all internal drives, disconnect all external drives, remove all but one stick of RAM (And if necessary, swap sticks on a second attempt if the first one fails, to see if the problem is memory related. Be sure in both attempts to only have the installed memory module seated in the second slot over from the CPU socket) and if you have any other external USB devices attached such as Bluetooth adapters, optical drives or headphones, disconnect those as well.

Then, remove the CMOS battery for FIVE minutes. Not twenty. Not two. Five. And during that five minutes, at some point, continuously press the power button on your case for 30 seconds and then release it. Reinstall the CMOS battery. Reconnect power. Power on the unit and go into the BIOS if possible. IF the system will POST and allow you to enter the BIOS, then find the option to load the default or optimal default settings which is usually located on the exit and save settings tab and select it. Save settings and exit BIOS to restart. Go back into the BIOS if possible and if it will allow you to do so, reconfigure any custom settings you need to such as fan profiles or memory XMP settings and then save settings again and exit.

Power off the system and reconnect the hard drive that contains your operating system. Power on and back into BIOS if possible. Set the device boot priority, save settings, exit and see if it will boot into windows.

If any any point you have the same problems as you had in the beginning, then you probably need to completely bench test the unit as well as adding components back in one at a time until you find which device is causing the problem. If the problem still occurs with nothing but the motherboard, CPU, power supply and memory installed, then it's highly likely you have a motherboard failure.