Due to a dead CD head unit, I bought an Ebay X3/Z4 head unit that, when installed, receives power (instrument backlights), but nothing else.

I also, tried to swap out the just CD assembly with the same result.

Is this a bad head unit, or is there some other "initializing" procedure? This is my first "post security code" BMW.

Any ideas, Before I go to the stealer?


David