To mount the cooler I needed to take motherboard out of the case and as I managed to put the cooler on place I wired all back again but when I pressed power button, nothing happened. I called to my friend and we got wires in their right places -> Fans started to spin but nothing else happened, "No signal". Then I noticed I hadn't plugged one 8-pin on motherboard. After plugging computer turned on but gave message "CPU is unworkable or has been changed, please recheck-cpu soft menu."(I read from internet that this happens a lot with ABIT IP35-E without reason or with slight meaningless reason like memory is not getting enough voltage) and started to make weird beep sound. I pressed F1 as it said and it continued to desktop without any problems, it worked without problems for maybe 15. In that time I managed to test the CPU temperature. Below 20 degrees idle and 40 degrees at 100% use. Then it suddenly went off without any sign. Now as I try to turn it on three things happen; The led in motherboard turns on, it makes klick sound and fans turn a bit. Have tested it with another power supply and with only processor in etc. So the problem is in processor or motherboard?
well forgetting the 8 pin connector wont mess it up. the temps make me think the kuhler 620 works fine. my ideas are this...
check the cpu and socket for burn marks. i once had a hair conduct current across the cpu and fry it. on an old athlon mp 1600. checking for debris on the pins is a good idea too.
minimize the components hooked up to the motherboard. unplug the drives, use onboard video if avail, leave one stick of ram and try it in each socket and try more than just that one stick it could be the bad one.
if you have another socket 775 computer around you can try your processor in it or vise versa.
if your computer gets that initial one beep, your CPU passed the bios check.