you need to run keyboard and motherboard hardware test to find if any of those broke. I'm not sure for specifics, some tests can be accessed through bios, others with a special key during boot up. Best option is to contact support and ask them for help with diagnosing the problem.
If you cannot/donot contact support, I'd recommend googling for some diagnostic software that would be able to check keyboard/motherboard for faults.
My best guess is keyboard broke, so you will need to replace the keyboard.