ich habe die PCB getauscht und die Festplatte läuft wieder, es wird aber leider nix angezeigt. Was muss man noch beachten wenn man eine andere PCB montiert?

Which PCB you had repleced?

I replaced these

Please refer the attached photo. The BIOS needs to be changed.

You can move the BIOS from your original PCB by using hot-air gun, then solder it on the replacement board. Please refer: http://www.datarecoveryunion.com/hard-drive-rom-chip-swapreplacement/.  Or you can find an electronics repair shop help you.

is that the bios chip?

Yes, it is.