Unless this is purely a coincidence and the video has failed try pressing the "Video status" button as this brings in a previously pre-set level, (that is if its been set?) however if this makes no difference then press "Display" and select "Picture settings", then run down and select "Brightness", then increase it using (holding down) the "Volume +" button, as there is the possibility that this has been turned off. All this said assuming of course that you have the proper JVC control for the set. (This is explained in page 34 of the manual for the set)