Radio/GPS Black Screen
 

I have a 2005 Chrysler 300c and recently the screen on my navigation system goes black.
In the AM when starting car it is lit and shows normal function. After some time it goes black screen.
The radio still works but can't use GPS. I've rebooted it by shutting car off and open and close door, still black screen.
While driving around for some time it come back on by itself.
I made a call to a radio shop and was told it is cold solder problem.
Does anyone know how to fix this problem, without going to the stealership?. Are there parts that you can get for this problem?.
Thanks