PlayStation 4 pro!

So I bought Devon a brand new PS4 pro as a Christmas gift 18 days ago.. it has worked perfectly up until last night/this morning. Devon was playing sonic & the game just froze so he unplugged & hooked it back up. Now when he tries to turn the system on the blue light of death light flashes & the tv says no signal. I've YouTubed & googled every trick & nothing works. & of course I've already misplaced/thrown away the receipt & I didn't purchase a warranty because I'm an idiot. Someone please tell me what to do & where to take it to get fixed. ...