Nav display issue, two navs tried

[Ramseyd]

I just bought a 01 e53 x5 and I love it but apon buying it the seller told me the factory Nav would play music but the nav display would not work. So he bought another and sold it with the truck. Today I installed the new one and the exact same thing is happening. What could the issue be? Could I have two units with bad displays? Is their a way to test the units?
Any help would be awesome

[alanber8407]

any update on this did you get it sorted ?