Ps4 controller connects first but then goes out?

When I press ps button on my controller, the ps4 goes on and the controller lights up blue. After a few seconds the controller goes out but the ps4 stays on. If I press the ps button again, the controller lights up blue but goes directly out again. On Bildschim me then indicated that the ps4 can't be started and I should connect the controller to the cable and then I should press the ps button - but that does not work because the controller does not connect to the ps. Can someone help me?

Start your ps4 manually

So press the front button.

Try connecting the controller.

make sure that every cable is firmly seated!

if it still does not work it is most likely due to the controller