I pluugged in a disc drive on accident while my pc was powered up!

I came home one day and noticed my comp had blue screened so I turned it of and restarted it. An error message came up saying cant detect drive abort or restart I noticed one of the drives making a noise so I turn of my comp unplug the drives to see which one is making the noise at this point my comp powers on and of posts ok it just keeps getting that error message. So when I go to plug the drives back in I forgot the power was on and needless to say my rig shuts down. I try and restart it and now it wont post it just comes on for a second then powers down. I thought I might have fried the psu so I tried a new one with the same result. I said well mabey I damaged my mobo, but b4 I spend money on a new mobo or cpu I thought id ask if any 1 had done this or heard of this happening or have suggestions on what to try b4 buying another mobo?
What I have tried so far is replacing the psu
pressing the start button to disperse voltage in the box
unplug drives and start comp with just mem, and cpu (when I do this the rig beeps 1 long beep then shuts down but when anything else is plugged in it doesnt beep it just turns itself off after 3 secs.
My motherboard is a ASUS M2N-SLI DELUXE Nforce 570 PCI-E AM2 MOTHERBOARD. An Ultra 600W psu, and a amd 64 6000+ dual core cpu any suggestions will be much appriciated.