I own a 2005 Chrysler 300C and my REC NAV unit (PN56038646AJ) has been having many issues the past few months. Some of the things that happen are screen turns off while music is still playing, music only plays on left side of the car, volume can't be raised or lowered, when you go to the NAV map the whole map just spins in a circle, etc... All of this happens randomly. About two weeks ago the screen turned off and it hasn't turned on since. The only buttons that are working are the preset buttons and the volume knob. I have taken the unit out and looked at everything inside it. None of the circuit board or parts look damaged in any way. Any advice on how I can get this fully functional again would be greatly appreciated.