I fixt my problem “Flashing Power-Button”
Finally, it’s very easy.
First of all, you go to this side: https://github.com/audiophonics/Raspberry-pwr-management.
At the bottom of the page is described how you have to proceed.
Use putty, start there with your IP-Adress.
login: volumio
password: volumio
Than follow the steps that described there. Thats all.
And after that, the power-button does’nt flash anymore. 
With best regards
tschuklo