HELP! Computer won't BOOT

[Reeper47]

Heres my specs first:
Gigabyte GA-8ik1100
Pentium Prescott 2.8Ghz
Radeon 9800pro
450w power supply

Ok now heres what happened,
One night i was doing something with the power cords underneath my desk and one kinda half unplugged due to my fiddling(i know, I'm an idiot). Next thing i know the computer is frozen, i restart it and ever since it just powered on with no post beep and nothing on the screen. So after investigating and figuring it could be the power supply i found that the 4pin connector plugged in on the motherboard was fried. I had a good look at the motherboard socket for the 4pin connector and it seems ok just a little bit brown on the plastic. So i tried another powersupply(a 300w) and this time i get the POST beep but its about 7 beeps. According to my motherboard this is a power error. When i unplug the 4pin connector and try and boot with just the 20/24 pin connector in it does nothing like before. So have i damaged the 4pin connector on my motherboard (which according to my mobo book helps give power to the cpu) or have i fried the hold motherboard or the processor or something. I have had a good look at the cpu and theres no visual damage. Also if it is just the 4pin socket thats damaged how on earth could i fix it cause the motherboard is no longer under warranty.

Help is greatly appreciated.

[Reeper47]

Here are some things I've tried by the way:

1. Unplugging everything and removing all add in cards
2. Wiping CMOS

I only get the Power error beeps when the memory is removed and the 4pin power plug is in.