Screen remains blank although at times the machine gives directions.

Tap on: the main screen. Tap on: Change Preference. Tap on: Arrow Keep tapping on the arrow till you reach Preferences 6 of 6 Page. Here you will find Battery saving preference. Tap on it. Tap on: Never dim screen. (I think your selection would be dim screen between instructions at present.). Tap done. On the next screen select : Device stays on when external power is lost. (A green tick mark should appear to verify it is selected.) Tap done.