PC randomly resets and after a reset a BIOS is opened

AdmiralMyxtaR

Reputable
Apr 24, 2014
23
0
4,510
Today I have got 3 random restarts, once when watching video and twice when gaming. None of the components were OC'd or overheated. Stangely enough, it resets like I pressed the reset button (hard reset), but then it opens an empty BIOS (only name is shown with a blue empty space), then restarts normally. I hadn't this problem before. What are reasons can be?
My PC configuration is:
AMD FX-8350
Radeon HD 6850
Gigabyte GA-970A-UD3P Mobo
Cougar PowerX 700 PSU
Hitachi Deskstar C7000.1 1TB HDD
I didn't do anything in BIOS, don't changed settings, nor reflash or etc...