ok, last week my desktop one night wouldn't go into screensaver, then the next day, after locking the pc, it would not respond to keyboard or mouse actions to get it out of sleep mode. I powered down the pc, and when I tried to power it back up there was no response. when powering on the pc, I don't hear the post beeps, I know the usb slots are getting power, and the hdd is spinning. I tried to boot with my windows cd, but again nothing. I have swapped the cmos battery, and video card, still with no success. I have narrowed it down to either the power supply or the mb/cpu. is there any way to test the mb for shorts other than a visual inspection?