Hello. So my motherboard is Asus Sabertooth Z97 Mark2. Today i get freez crash in BIOS UEFI. The mouse was frozen, keyboard does nothing, but the various component monitors was displaying properly(the fans under FAN Profile was spinning, the CPU Temperature, CPU Voltage, and Motherboard Temperature showing status actually correctly). Only mouse and keyboard was not responding. What can caused that crash? Or my memory is faulty or motherboard? If i remember i plugged pendrive usb when i was in bios. That is the reason or maybe not? But i was try to reproduce this and no crash again. Mobo is Asus Sabertooth Z97 Mark2 Psu is Corsair 750 RM ram Kingston Hyperx 2x8gb DDR3 1600mhz cpu 4790k no OC. Also i tested memory with memtest86 20 hours without error.