yes. NC boots off the SD card and. if you left your autonootered SD card in, it is basically rerooting itself. nothing displays on the screen. during autonooter. it works when you plug it into your computer because the autonooter script has to talk with adb on your computer to root. after autonooter does its thing, it auto rebooted and stuff shows on screen like normal. this is what you are seeing.
turn off, take it out, bootup, profit