Two buttons on the left side of all iPhones are used for turning the volume up and down. If these buttons stop working, they may only have been disabled. Some people choose to disable these buttons after selecting an appropriate volume level so that it never changes. Others disable these buttons by mistake. Either way, changing your volume settings is easy and takes only a few seconds.
Tap the "Settings" application from the main screen of your iPhone.
Move the "Change with buttons" slider from "Off" to "On."
Press the "Home" button to exit the "Settings" menu.
Tips & Warnings
- If your iPhone's volume controls are broken and not disabled, call an Apple retailer near you to have them fixed. If your iPhone is still under warranty, you probably won't be charged for this repair.