Ender 3 Max Neo | Booting problems

Hello,
I’m still quite a newbie and have the following problem.
I haven’t used my Ender 3 Max neo for about 3 months.
Today I wanted to turn it on and it doesn’t boot properly.
That is, there’s only a Creality screen on the display, a few numbers at the bottom, nothing else happens.
I’ve tried flashing the display and the motherboard, but that doesn’t work either.
Does anyone have an idea?
Best regards