I encounter a low rate of successful POSTs, and I'm saying that because after few hard reboots I manage to power my system.
When POST fails there is 1long-3short beeps, which means No Video Detected. I can't fully confirm the video is fine, but I will in future and I doubt video issue.
Sometimes there is no beep code, but in much less cases, like 1 in 10 or less.
I also noticed that after clearing CMOS settings even if default is loaded, POST succeeds.
If POST is successful, system is stable and operates in normal parameters.
So any ideas how to isolate the problem? Yes, first I'll test the video card to a friend, and then what?