Moto G on cyanogenmod 13 has a black screen but phone seems to be running in background I have the CM13 installed on my Moto G (Falcon). 

Last week, I left the phone on charge longer than usual and I came back to find dark screen. I have tried restarting it and I can feel the phone vibrate when it powers back on, however I cannot see anything on the screen. When the phone is "on" or I press the lock button, it goes from the shade of black to a shade of gray. 

I have tried connecting it to the adb but adb shell doesn't recognise any device.

The phone must be working though as the alarm goes off every morning.

I have tried looking at several solutions on the web with little success.

Any help is appreciated.
I have faced the same issues too and your best bet is to reset the phone via a custom recovery(assuming you have one installed) since you flashed cm13.