My HP Envy 360 (15-u337cl) won't boot up. The only light that comes is the one on the power button. It lights up, I hear the fans turn for a second and then it stops the boot up process. Nothing else happens and it repeats that process over and over every 4 or 5 seconds. I tried the HP forum but none of the links that show how to do a hard reset on a Envy 360 work. They're all dead links. Can anyone help?