I have a 2007 Chevy Tahoe LT with a DVD player in it. Just got it. Somehow the DVD volume is stuck at 13, and when you plug in headphones you just get a static sound. There is no in dash nav. Do I have to take it to a dealer to be reflashed, or do you think the DVD player is Junk. I believe the dvd is factory since a GM screen shows up when you first turn it on. Any help or suggestions would be greatly appreciated.

Thanks