I have an HP 19 all-in-one PC that won't start up. I've checked the power cord and have done the hard reset by unplugging the there cord and then pressing the power button for 10 seconds. Nothing. I took the back cover off and the light next to where the power cord is plugged into the back of the computers is one when it's connected to an outlet. Any ideas to reboot or turn power on or reset it to get power on?