[V8] Radio code and radio buttons unresponsive

[gbmarc at cox.net]

Well, thanks to Ed for recommending Stammler Audi in Colorado. They were indeed very helpful and could supply the radio code for $120 less than my local dealer! (i.e. free!) 
 
However, it hasn't solved my problem. 
The car I purchased has a Delta CC radio that is in some unresponsive  mode.  Currently it comes up in AM 1520 but none of the buttons have  any affect on changing anything. 
So, now that I had the code I tried pulling the fuse and totally 
disconnecting all connections at the back but  it didn't change  anything. 
It doesn't even come back in 'SAFE' mode after the power is turned  off.  It's like it never lost power or as if the security feature is  not working. 
The only time I see any affect from the buttons is if I turn the radio  
on with some of them depressed. For example, I can hold the TP button  
down, switch on and get into GALA change mode, or I can press a couple  
at the end, switch on and I get "NO CD". Other than that it is  
unresponsive. 
 
I was wondering if perhaps one of the buttons is perhaps stuck in  
permanent depressed mode? Two of the FM presets don't click properly  
like the others do when pressed. 
 
Mark.