Cell phone does not go on but the alarm clock still rings?

I woke up this morning and my Huawei phone did not turn on. The alarm clock works fine. After I restarted it using the button, the screen in the middle flashes white green for a few seconds before turning black again. After waiting 5, the cell phone worked again. But after I hadn't used it for 10 minutes it didn't work again and I repeated the steps. I'm already out of the guarantee, has anyone had the same problem and knows what I can do and whether something can be fixed at all?

It works as though.

Charge for 2 hours.