ABIT AB9 QuadGT - beeping with FF error code

Hi,

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?