a thick line appears when i press the home button or the power button

[AC Question]

i saw a line appeared on the screen on the rightside of the password bar. it happend after updating my device s4 GT-19500.... that line just pops-up when i press the home button or the power button

 

[B. Diddy]

Duplicate, see response here: http://forums.androidcentral.com/sa...ng-when-i-press-home-button-power-button.html. Thread closed to prevent parallel discussions.