MacBook Pro touch bar display is off.

I'm not sure why or when the touch bar went dark, but out of the box, it was lit and functioning correctly. I migrated data from my older MacBook Pro and at some point after that, the touch bar went dark. I tried restarting in safe mode, but the problem persisted.

• Keyboard is lit.
• It seems the touch bar is somewhat functional; I can adjust brightness and volume if I poke around blindly on the touch bar.
• System > Preferences > Keyboard > Touch Bar shows "App controls with control strip"

Any ideas?