Nav Screen Dark. software issue? Help!

[jjj88]

I have a 07 E70. For the pass three month, my Nav screen went blank 3 times. The Nav screen still function well. You can just see everything under the light. I took to the dealer today, they told me first it was a know issue and can be fixed by software upgrade. Then he called me later and quoted me $5500 to replace the nav screen including computer system.

I am not very convinced that I really need to changed the whole unit. Does anyone know the fix of the problem.

If it is a software issue, I am willing to learn how to code to save the $5500.

Please help and provide any advice.