Thanks for your answers.
I did forget to mention one important thing - motherboard is fully functional!
Almost though. Sometimes it's hangs and forces PC to restart unexpectedly, the screen freezes for a second, sound also 'freezes' and then restart, no blue screen. Looks like power failure to me so i decided to take a look at the MB.
This is not a cheap sh... , its really an expensive and quality one, but definitely there's a problem. Whihch I want to fix by replacing this fuse, if it is fuse. But what's the current rating? And is it really a fuse?