Navigation-backup camera not working

[gart1021]

I'm new to the 4runners so I may ask a dumb question.
Display just says insert DVD. There is no DVD to be found. I can not go into settings. When in reverse it does not switch to camera view.
2005 limited

 

[TRDCal]

Maybe it wants you to update? Try unplugging your battery. This should reset the nav unit and hopefully at least allow you to access some settings. Since the radio is on the hot bus (always gets power), turning the truck off isn't enough to reset it.

I once f***ed up the update on my aftermarket indash nav and I was sure the arse had fallen out of her, but disconnecting the battery reset the unit back to normal.

It's a long shot but it's better than no shot