After clicking the power button on the computer today I ran into a problem: no video appeared on my monitor, and my keyboard and mouse weren't working; when i tried to turn it off, it wouldn't--i had to flip the switch in the back. It seems that after clicking the power button the system is running fine; there are no beeps and all the fans begin spinning. However, after 5-10 seconds everything stops. Then a few seconds later it all starts turning again, but nothing comes up on the monitor and the keyboard and mouse wont work and i can't turn it off without having to flip the switch in the back. Yesterday the machine was working fine. I moved it downstairs today before it stopped working. If anyone has any ideas, or a solution to this problem i'd be very exited. Thankyou.