System wont power on

[Bambi]

so yesterday i decided to hook up another hard drive to my system and after i connected everything togetehr again, my system would not power on. i unplugged the hd but still no luck. I took everything apart and connected only the motherboard. Doing so let out a constant long beep or whistle. Is my power supply gone or motherboard?

http://www.youtube.com/watch?v=0Us0Xp5hWYE


250gb hd
e8400
MSI P7n platinum (i think)
2 x 8800gt
1 dvd-r

antec 500w phantom psu

 

[Dangman]

Reseat the RAM

Also take a look at this:
http://www.pantherproducts.co.uk/Articles/Motherboard/BIOSbeep.shtml

 

[Bambi]

I updated thread title and my first post. I try ressiting ram now.

 

[jerb]

Ok, take it step by step.

take out all the expansion cards, if your mobo has onboard video use that instead of the 8800's. using 1 HD and one stick of ram try booting. if that doesnt work try different sticks of ram.

if you want to test your PSU, take a paper clip and short the green wire to any black wire.... so long as it turns on your fine