Predator Helios 300 Ph315-51 shuts down while gaming.

MaverickNathan1

So this isn't my first post on this topic, but since the whole of the internet could not come up with any solution to this problem, I am asking this question again. My computer either totally shuts down or freezes up with a black/pixelated screen while playing. I am mostly a CSGO player, and this happens as soon as any graphically challenging situation happens in-game. This is a problem that I have battled with for over a year now.

Here's the sequence of events in order over a year: -
1. Last year, it was a thermal problem. Same symptoms. Temps were touching 100C, so I repasted my laptop with some TG Kryonaut, along with undervolting and maxing out fan speeds to play my game. That seemed to solve the issue. Still, within a month or two, my temps were back upto 96 - 98, but my game still worked so I didn't think more.
2. This year, in January, a couple of keys stopped responding for me, so I got a keyboard replacement as well as a full service cleaning/repasting of my laptop. My temps seemed better than ever after that. I was playing at 76C but only for 2 days. Then the black screen/shut down problem started happening again and this time I could not even blame the temps.
3. This time I did a bios downgrade. I went from 1.26 to 1.15 and it solved my problem. However, dumb as it is, regardless of how many auto updates I turned off, the bios used to get updated to 1.19 every 2 days or so and the problem started returning a couple days after each upgrade. Each time that happened, I did the downgrade again and it solved the problem (for a couple of days). Until yesterday, when the bios downgrade too wouldn't do anything. 

Things I have already tried 
1. Repasting
2. CPU Undervolting
3. Bios Downgrade
4. Multiple clean OS reinstalls.

Absolutely not a ***** thing works. At this point I am willing to try literally anything hardware or software.
This is the latest iteration of this stupid problem. Literally 10 seconds into CSGO.