My sleep button does not work. How do I turn off my iphone?
My sleep button is inop. How do I turn my phone off?
iPhone 4 (8GB), iOS 8.3
Check for debris or dirt around the Sleep/Wake button and clean it with a soft cloth. Remove any case or film. If you've followed the steps above and the Sleep/Wake button still doesn't respond, if it works intermittently, or if it's damaged, contact Apple Support to set up service.
Get help with buttons and switches on your iPhone, iPad, or iPod touch - Apple Support
In the short term, you can turn off the device using AssistiveTouch. To turn on AssitiveTouch, go to Settings > General > Accessibility > AssistiveTouch. With AssistiveTouch on, open the AssistiveTouch menu and tap Device. Touch and hold Lock Screen until "slide to power off” appears.
Use AssistiveTouch on your iPhone, iPad, or iPod touch - Apple Support