First of all sorry for posting that much, but I'm not able to find solutions through other means [like YT or Websites].
It won't load into the home menu at all, but the screens work and there was no visible damage inside the console. [Video for visualizing my problem]
I tried updating the console and it didn't resolved the issue.
Here are my 2 previous posts with the difficultys I faced. [I post the links in, because of the off chance, that one of the issues could be related]:
Posted by Danny0Blau