Hi Kevin,
thank you for your reply. Please note my system has been running flawlessly in the last 6 months or so, so this is not a fresh out of the box issue for me.
I did everything you said. The motherboard has been taken out of the chassis, every component except the CPU and CPU cooler has been removed. No change. Also tried both RAM sticks separately in each RAM slot. Should I try without the CPU cooler too? (I am using an aftermarket cooler master)
If I boot the system without the BIOS security jumper, then the CPU HOT led doens't flash. However the board seems to be stuck in a boot loop. Sequence: 0014 - dd26 - dd44 - 0021 - 0003 (not sure about the first 0014). And no hdmi video output. So it's the same sequence as when the jumper is there, but without the 0010 before the CPU HOT led flashes.
I will do one last try tomorrow, a friend will lend me his PSU. Just to rule bad powering out, but without much hope.
Can you please explain what does the CPU HOT led mean. If it has to do with cooling, I'll try to use the provided intel cooler to make sure. Also can you indicate if the CPU or mobo is more likely to be at fault?