What causes a laptop to suddenly turn off?

Question

Batteries

Sometimes the HP Pavilion G6 laptop suddenly turns off. Yes, I googled, but the solutions don't work for me. Recently, I was spinning a laptop because the cooler was stuck and it literally did not work. I shifted it a little and, in principle, the laptop began to work better than before. For comparison, the tanks had 30-40 fps, and it became an average of 60.
It also needs to be clarified, I think that I work with the laptop completely from the mains, since the battery died (windows saw it, but did not charge it).
So, after yesterday's trip to the dacha (I also turned on the laptop from the mains - using an extension cord) - now the laptop does not see the battery (the battery is not detected) and sometimes it turns off spontaneously. After about 5-10 seconds, it can be turned on again by pressing the power button. Prior to this, she does not respond to pressing. Also FPS in tanks has decreased. Now it is about 50, but sometimes it drops sharply to 20-25, which was not the case before.
I tried to unwind, checked the cooler - everything is fine, I checked, maybe something got inside (wiped everything) - no, it doesn't matter.
What can you suggest in this situation? :)

Answer 1

as a rule, if the fan starts to act up, it is better to immediately completely check the cooling system, thermal pastes and generally monitor the temperature.
Overheating or its consequences - the first possible reason for spontaneous shutdown
. The second possible reason that you may have is a failure in the laptop's power board. (Symptoms - does not see the battery at all)

Answer 2

Here's what AIDA says in terms of temperature:
CPU 66 °C (151 °F)

Is it idle? Then - a lot. Under load, it turns off from overheating.
The percent heats up - the frequency decreases. Cools down - again the frequency rises. And there are swings.