Philips GoGear HDD6330 MP3 Player "thin black line across" Questions

...thin black line to the right of the screwdriver tip is the cable clamp, this needs to be gently hinged upwards using a very fine flat blade screwdriver to about 40 degrees, full across the top of the ...

thin black lines have appeared across my iPOD screen where the volume/track bar is. I don't know why or how to get rid of them? Its either because you dropped it some where or its because u charged it