battery replaced, sat nav and radio kaput :-(

Morning all,
just had the battery changed on my P38 2001 RR, now i dont have any sound from the front speakers nor does the volume work via the steering wheel or radio unit. The sat nav also has a problem, all i have is a white screen , any ideas ?? Is there a 'reset' button that needs a poke ?
Kind Regards
Merry Christmas

Andy

same as Trev's problem, any one know how to disable the sat nav ?

I've had a poke around in the boot but it seems to be bolted in from the back so cant unplug, ???

cheers

Andy