Start-up difficulties with the laptop?

Hey with me the laptop has recently gone out because of the empty battery. Nothing unusual! But the side I was on remained open. Where I wanted to turn it on now, it did not work. The battery is full! The screen goes gray for a moment and then the computer goes off again. How can I get it to work again?

Try using Alt + F4 and then press the power button until the laptop restarts

Try to take out the battery for 10 minutes and maybe Only start with cable.

Sorry, does not help.