Thanks to everyone for the valuable inputs. I am going to rma the drive and also get a new power supply, hopefully it will never happen again......
I have been trying to get the computer to boot without the hard drive, but it is simply not cooperating. All four diagnostic leds light up no matter what I do. I have changed jumper settings here and there, video card in different pci e slot, tried my old computer's psu, tried just one single stick ddr...... nothing made any difference.....
There are four power connections to the dfi nf4 sli-dr board. I am not sure if this means anything: I unplugged one connector at a time to see if at some point the board would react differently. Unfortunately no, it still reacted the exact same way. Although it is hardly a proof, I wonder if it is an electrical problem, by which I mean the power is not getting to some of the chips. I even took the cpu out and it still made no difference. I wanted to see if the cpu was getting any power at all. After I turned it on for a few seconds and powered off, the cpu was indeed slightly warm, so at least I know the cpu was getting some power.
From 486 to p4 I have had some decent experience building computers. There were always one or two minor glitches that worked out fairly quickly, but now I am almost out of ideas to try with existing parts I have here... no post since day one.