I just finished building my first computer. When I turn on the computer, the monitor turns on, then just goes into power save mode, and a second later, it turns on, and goes into power save mode, and so on. I tried putting the memory in different slots and swapping, and I took out the graphics card and put it back in. One time I powered it on and the monitor stayed on for about 5 minutes, but then it went into the on/off cycle again. Why is the monitor turning on and off?