My computer suddenly slowed down. I checked the RAM with memtest and the result is ok I havent wrong processes, anti-virus did not show anything, so I thought it was overheating.

I installed a new fans (one on the back of tower, second in the radiator Pentagram Karrakorum).

Next, when I turn on my computer, the codes on motherboard are changing from init states sequentially to state FF - which is good, and immediately (from the beginning) motherboard starts beeping like an ambulance. You know, iioo iioo ... The temperatures are normal. What can cause strange behavior of my motherboard?

Maybe the fault is in power supplier? Processor? Any ideas?