PS4 turns on without a power cord?

When I pull out the power cable from my PS4 and wait a little longer and then I press the power button, my PS4 turns on, so the beep comes, the light shines and the controller connects. But it doesn't start up, so at least there's no picture. After about 10 seconds it goes off again. I think this is not normal and assume a defective power supply. Also, sometimes it just turns itself off when you use it. Does anyone have any idea what the problem may be?

This works because the electricity is still flowing.

In the power supply there are so-called capacitors, which are small batteries that are supposed to compensate for jumps in energy.

This is the same effect if you unplug a vacuum cleaner and then touch the contacts immediately afterwards, then you get a slight electric shock

Many devices briefly "switch on" again. Residual currents that are still in the device.

to put it simply!

that's enough for the led. Sometimes for a short flash, sometimes for a few seconds.

that's why you should wait up to 5 minutes after pulling the power plug if you intend to open the device

It is completely normal for the power supply to continue supplying power for a few seconds after the plug has been pulled out. This is the case with most power supplies. The USB power supply unit that you use to charge your mobile phone also behaves in the same way.

Power supplies contain capacitors that store electricity.

However, it is not normal for the PS4 to switch itself off during normal operation.

But why does she just go out like that sometimes or what could be the reason?

No idea

What can be the reason if she just turns off like that?

Try the tips here: https://www.mynewsdesk.com/de/minitool/pressreleases/ps4-schaltet-sich-von-alleine-aus-so-behebt-3029424