Bryen61616

Hello people please help me if you knew or it has happen to your W204. This is what happen when I remove the radio unit to see if there is connection in my Radio Unit so I could add a back up camera , after I removed the radio out then I unplug all the wires and then I put it back in then when I push any buttons on the Radio Unit nothing is working and the all the light are not illuminated but the Radio is still working by using the Dial or the buttons on the steering wheel . I'd check all the fuses in trunk and in engine they are all working but I don't know the Radio buttons are not working , I push the Radio Power to turn the radio off it's not working. I took the Radio out and the fuse in the back of the Radio Unit it's ok too. What happened ??? . So if anyone knew about this or had happened to your Radio please REPLY me.
Thank you people ...