It looks like there are a few threads for this problem I do not see any solutions that have worked for this problem. My Predator G6 desktop has a flashing light under the power button. It actually looks like the whole panel where the button is attached if flashing (u-shaped panel). I've tried unplugging, tried to turn off the power switch next to the power cord input, tried holding the power button for 30 seconds after unplugging - nothing seems to work. I've had half a dozen computers and all except this one lasted until the operating system was no longer supported. This one I've had for only a few years