Windows 10: Laptop constantly overheats, could heatsink be the issue?

I am a retired repair technician, my memory is shot so i dont remember everything, i do remember how to properly clean and install new thermal paste, i have done it twice using MX4 and there is really no dust in it either

Sometimes it gets so heated i can feel it near the touchpad, temp monitor shows it regularly in the high 60s and it reaches mid 80s sometimes, its an i7 4712hq processor, it appears to be throttling as well because the FPS in a game i play has dropped from around 25 to 15, sometimes it hits 12 and im on minimal settings

I have a 2nd laptop of the same model that recently died due to charging circuit but it performed a lot better and didnt have cooling issues

:)

 

Random laptop crashes in games.

thats alright bro, If it does turn out to be an overheating issue, I'll let you take all the credit for suggesting it

 

Updating windows 8 to 10 my laptop will overheat or not?

OT: Overheat issue.

Updating windows 8 to 10 my laptop will overheat or not? If will overheat, why?

 

Samsung laptop boot failure and overheating

I have a Samsung NP550PC7C-S02UK i7 laptop. initial symptom windows starts and spinning dots in endless cycles and fails to boot to windows login. automatic repair also fails to load. The laptop overheats and "pops" and shuts down. I have tried booting from USB and DVD - same failure to boot issue.
Removed heatsink and fan - clogged so cleaned and replaced thermal paste. The issue still remains.
removed HDD and loaded in a PC - diskcheck fixed some issues. Put back into laptop and still no boot to login, usb, dvd and auto repair fail and still overheats and cuts out???
Anyone experienced this type of fault? I suspect either cpu, gpu damage or even mobo? helpful suggestions please