why didn't the screen off after closing the flip cover in my friend's galaxy s5?let me know please.

[AC Question]

Is there a problem in setting or in hardware?

 

[AlphaTango414]

See other thread. http://forums.androidcentral.com/showthread.php?t=659600

 

[Samuel Orris]

Is there a problem in setting or in hardware?

Set up the setting again in the Auto Wake/Sleep function.
Otherwise download this apps from android store. https://play.google.com/store/apps/details?id=com.MarksThinkTank.FlipCaseControl&hl=en