I've had this machine for just over a year and have turned it off only about 6 times. As I have no video card in the tower, I am using a VGA cable. When I turn on the monitor, it searches for the cable type, HDMI/DVI/VGA, the screen goes black for a second, comes back indicating VGA then the monitor goes to sleep. I thought there was a power switch on the tower. The setup unstructions are about as useful as a screen door on a submarine. Can someone help?