Toshiba Satellite shuts down before boot

[boomerCCT]

I am repairing a Toshiba Satellite C655-S5068 that was dropped. The screen was obviously in need of replacement, so I ordered and installed a new screen. I also put in a new HDD. The laptop turns on but will not boot. It generally does not go any further than the Toshiba screen before it shuts down. One time I got it to go as far as to start Windows Repair, but then it froze and I was forced to reboot. Any ideas on what may be the cause of this? I'm trying to try every possible route before I go all out and say it needs a new board....

 

[Desolation]

you might have to reseat the heat sinks it could be over heating or there's more damaged parts than what you replaced