Radio does not work after R&R

Hello! My name is Jan. I just installed an aux in option to connect a bluetooth module. After I reinstalled the cd / radio unit, the system apparently does not recognize the unit. There is no power on the component but the screen above works and shows the radio stations (0.00). It also does ask for the code each time I turn the ignition on. I tried the FFW / A.MEM / PTY combination but nothing changes. I don’t think its a bad fuse as. The orange connector has power on the lower right lead of the connector but the CD unit seems to be dead…
Do you have any idea what the issue could be? Could I have burned out a circuit while soldering the cables to the main board of the CD-unit? Many thanks for your help and happy holidays!