the top on/off button doesn't turn off the screen

[TonyG]

For the last 2 1/2 months, briefly pressing on the top on/off button would turn off the screen, but today something has changed and this brief press no longer works. Any idea which setting controls this behavior? I looked everywhere I could think off, used Spare Parts--all to no avail...

 

[milrtime83]

Don't know that you can change that with a setting. It may be defective. Does the button work with a long press? A longer press should bring up a menu to Silent/Airplane/Power off the phone.