Laptop won't boot

Hello,

I have an HP Pavilion DV7 laptop and it recently stoped booting up unless I allow it to get hot. When I hit the power button the power light comes on and the caps lock button blinks and the fan turns on but the system won't boot. I swapped out the memory thinking that was the problem and tried each slot and still didn't fix the problem. Only but a freak incident where I forgot to shut it off did it power up after it got really hot from letting the fan stay running and it booted up just fine. After closing the lid and later coming back to it I opened it to a black screen that would not reboot from sleep mode. I powered it off then back on let it sit till it got hot shut it down then hit the power on and it booted just fine.

What would cause my laptop to only be able to boot after it sits with the fan on and getting hot? Is there a fix for it?