I have this model:
MacBook Pro "Core i7" 2.7 15" Early 2013 2.7 GHz Core i7 (I7-3740QM)
Intro. February 13, 2013 Disc. October 22, 2013 Order ME665LL/A Model A1398 (EMC 2673)
Recently it started shutting down randomly and I took it to a local repair shop. Tech guys told me the problem was with the power controller board (because of the constant overheating) and that they had fixed it. However, the cooling system (the radiator itself) was failing (probably out of gas inside due to them) and needed to be replaced. They failed to find a replacement part (since the laptop is old) and recommended me to restrain from overloading the system in the meantime. The laptop is now running smoothly. I'm measuring the CPU temperature with Macs Fan Control and it is showing 103 Celcius degrees on the CPU cores under the heaviest load possible (which according to the tech guys is a way too high). However, according to this answer:
https://apple.stackexchange.com/a/284437/330383
there is an Intel defined spec for my CPU:
The Tjunction value (value when the processor starts to slow down to avoid damage) is 105 Degrees.
I never measured the CPU temp before the incident but I feel it was always running this hot from the very beginning.
So, please help me understand - did the radiator really fail or it was just a random power controller problem?
One more thing: I was using a faulty power adaptor for some time which had an overheating connector - THAT could have possibly caused the damages to the power board. To my mind, it may never have been connected to the CPU overheating.