First check the power cord make sure its plugged in to both SU and Monitor. Next check and make sure the main power supply switch is turned on. Next check VGA HDMI cable on both ends ensure its properly inserted and screwed down. Then finally ensure the wall plug has power. If all of this fails change the power cord if it still wouldnt power on, then start looking into a more advanced hardware diagnostics if you have the expertise else refer to directions on how to.