Head unit screen dead after alternator change

[PhilUK]

Hi all,

After a good search I couldn't find an answer to my problem so thought I would pick your brains.

Further to a recent alternator failure and replacement the sound system in my 2003 X5 3.0d stopped working altogether. I checked the relevant fuses in the front and rear compartments but both were ok. Also tried the neg lead off the battery for 30 minutes which did bring sound back to the car but still a black screen on the head unit (thank god for steering wheel controls!).

The illuminated buttons are lit on the head unit so it is definitely getting power.

Any ideas?  :'(

[PhilUK]

Anyone??  :'(

[sleepyfolk]

Have you had a look at the carphonics website, he describes some common faults on there and the fixes available