My laptop does not go out on just then immediately?

My laptop is not working somehow. It is powered by electricity. When I turn it on, it goes on for 2 seconds and then off again

what could that be?

Have you ever removed the battery and then tried only with cable?

A thermal problem, because fans dirty.

Or a "hanging" on / off button.

So, as a remote diagnosis

If the battery is not screwed tight, you could take it out of the laptop and just leave it there for about an hour. My battery can simply pull out the back without screwing.