I got home from work to find my pc off. A storm had just passed through so i thought the power had shut off for a time. I started it up and i couldnt connect to the internet, so i restarted it. Thats when my problems started. All my computer will do is, everything will turn on, fans, lights, LED on mobo is on, and all opticals. Then after about 5-10 seconds it will shut off for about 20 seconds and restart the cycle all over again. It will not put anything on the monitor, nothing for the BIOS or POST comes up, no error beeps occur, no error messages. It just starts, then keeps restarting every 10 seconds. I cannot get it to stay on. The only way i can get it to stay on is to put the PSU into 230v. When its in 120v it does the restart problem. But when i flick it into 230v, it stays on. It will not boot, no POST screen, still no activity, but it will stay on. Could this be my PSU? Is it my motherboard? Ideas please!!! I live by my computer, I AM freaking out. Please advise!

PSU: Turbolink ATC-CW500P4
Processor: Intel Core 2 Duo E7600
Ram: 4 Gigs OCZ ???
VID: Nvidia Geforce 8600GTS 512mb

If you have a digital volt meter you can test the PSU. I can supply you with instructions if you want.

from what country are you??

Setting PSU in 230V mode is VERY no-no on 110V grid. (Truth be told, switching to 110V mode on 220V grid is much bigger no-no)

Obviously, your PSU got damaged during that storm. Power surges tend to do that.
PSU is relatively cheap replacement, but switching the input voltage might've done, but not necessarily, some further damage to the board circuitry.

Try resetting your BIOS. Either find the header for this -- Usually listed as JBat and move the jumper from pins 1-2 to 2-3 with the power cord disconnected OR remove the CMOS battery with the power cord disconnected.

Has worked for me in the past.