993 radio
 

I hope someone can help with this. I bought a 993 Cab a year ago. It has a Porsche stereo with an upgrade Becker 6 disc CD player in the front boot. Recently, I had to take the battery out of the car. I read the instructions on how to re-address the radio and enter the code, but now when I attach the stereo face plate, the display just shifts between power on and power off.
I'm getting tired of hearing myself singing.
Can anyone help me return my car stereo to its former level of operation? I have the radio code with my paperwork.
Thanks so much
Brian