x2 on my 06 IS350.
The screen will not come on and stay black; however, when I try pressing the screen, I can hear the beeping sound it normally makes me when I select something. I can change radio stations and the climate from remembering the positions of the virtual buttons, but the screen is still black.
Funny thing I noticed is, during cold starts, my nav screen will work and everything would be fine. But after driving for a while and shutting off the car, and turning it back on, the nav screen will stay black.
I already tried removing the battery cable for 5 minutes, but that didn't fix the problem. My warranty JUST expired (52K miles) on my car too, so I might just bite the bullet and have the dealer take a look at it.