PC Keep shuting down when playing game


New Member

So my pc is broken and i decided to go to my garage and take out my 8 years old pc with an I5 4690 and i plug a RX 570 4GB on it and start running a stress test.

Cinebench is running fine all, but when i start the heaven that is when i start finding problem.

the moment Heaven finish rendering and start running it immediately restart my pc, so i decided to try another game like CSGO, it's running fine in 10-15 minutes before instantly restart again.
then i open Crusader Kings 3, this time it shut down immediately after the game is opened, the same thing happen with MHR, Control etc.

Please note, i already change the thermal paste for both the CPU and GPU.

then when i scroll down a little, i noticed something weird, most of it hit 100c. is it an error reading or something else?

also, is this normal reading for the cpu?