C720 - C720P Screen is Dark (Not Dim)

Issue: Screen is Dark (Not Dim), device has power appears to be on and functioning.

Cause: This occurs from not using "Exit" command in linux during reprogramming of the device serial number. This will lock the device into the dark screen mode, even though power is going to the LCD power board.

Resolution:
Esc + Refresh + Power to put the device back into Developer mode. Press Control D and delete the local user data. Return the device to OS verification mode.
            - Reprogramming must be done again.
            - Improper exiting of the linux command during serial programming process will write a file to the devices Internal SSD Drive.
            - Removal of the "infected" SSD drive and insertion into a good brand new working logic board will cause the same Issue.

Additionally:
If you replace a logic board and reprogram and it is working fine. But you close the lid and it goes dark screen but you get an audible tone. Then you have a SSD drive that is incompatible with the logic board.
            - Solution: keep swapping SSD drives. Once a compatible one is installed the device will boot immediately when the LID is open.