GPS Navigation Unit is blank
 

Sorry if there is a whole guide for this, but I really tried to look before I posted. (new guy)
2006, with just a bit over 50k miles.
It first started with the display screen going fuzzy. I would take out the disc, turn my car off, and then the mazda log would show properly then.
I would insert the dvd in, and it worked fine. That lasted about a week.
Now it doesnt want to display at all, I can move the stick, and hear the chirp when I press buttons.

On a semi related note, ever since I bought this car, when it was a yr old, the buttons on for the navi wouldnt respond sometimes, you would have to press it down hard.