Looking for help finding the issue with my radio/nav on my 2014 gmc Sierra. 4 days ago my screen for my Rad/nav was black and didn’t work. Checked the 20amp radio fuse and it was good. Started driving and all of a sudden could hear some audio from radio. Could not control audio and still black screen. When I stopped the audio from the radio would not shut off unless 20amp radio fuse was removed. The next day the radio/nav worked fine for a day. Today again black screen and no radio/ nav operation. Any suggestions?