I have a fairly new computer, updated to the latest version of Windows 8.1 . On random ( daily ) occasions, the monitor will shut off and start 'clicking' back on and off -- the power button will light up green, the screen will go from dark black to back-lit black, but a second later ( before any picture displays ) the monitor clicks off again... and then lights up... and then clicks off... and then lights up, and will continue doing this indefinitely.
I have tried two different monitors, two different power cables, two different VGA cables, even plugging the computer in to two different power sources. The only solution I've found is to unplug the monitor power for an extended period, and then plug it back in and hope for the best. ( there may or may not be a correlation between how long I leave it unplugged and how long before it turns off again ).
The computer itself doesn't shut down during this time. I've changed every power setting I can find to ' please don't shut off, or sleep, etc '. Occasionally I feel like my monitor is making a high pitched whining noise when it is being used... but the fact that I'm experiencing this problem with multiple monitors concerns me.