Did you try rebooting the Sync 4A screen?My 15” display failed to startup yesterday morning. Black screen, as if it lost power. But.. it showed the camera images when I shifted into reverse, and the truck was 100% drivable. I did two things, not sure which helped. I ended up shutting the truck down, locking the doors, pushing the button on the charge port several times (in case I messed something up when I disconnected the charger) and walking the keys away from the truck for about 1/2 hour to make sure it went asleep. Bottom line, it booted back up just fine, no problems since.