Laptop screen goes black and has to restart?

I have had the problem for a few days that my laptop screen just goes black and I can't do anything anymore and have to restart it. I don't know why, but if I listen to music, for example, the music also stops playing. I also tried to just close it and open it again, but nothing helps because he continues to breathe or whatever you call it.

Feel the pulse, maybe he's a little stressed / s

No seriously, maybe a problem with the cooling and an intermittent interruption of the power supply.

Not closing it, that doesn't help with most laptops, because they don't shut down, but just switch to a kind of energy-saving mode.

Which model is it?

Unfortunately, I don't know which model it is right now. It's from the Medion brand and I've had it since last September. Maybe the battery has lost something because that happens more often when it is around 30%. I also had a liquid accident with the laptop where I needed a new hard drive but they told me that everything would be ok with the battery and that was a long time ago.