Sounds like either it requires resetting or had failed.
Let’s try resetting:
Power on the device and wait for the lock screen to come on.
Hold power button down until the (power off, reboot, or silence device) menu comes up.
Press and HOLD power off selection! It will pop up a screen that asks if you want to restart im SAFE MODE! (Thats the missing element!)
Select yes and when the screen goes black quickly press and hold down the + volume (up volume) button until the factory reset screen comes on
Release the button, use - volume (decrease button) to select choice and power button to select choice!
From the ifixit website.