Appendix A Tips and Troubleshooting 115
 Download and install (or reinstall) the latest version of iTunes from www.apple.com/
itunes.
If you can’t make or receive calls, send or receive text messages, or access email or
the web
 Check the cell signal indicator in the status bar at the top of the screen. If there
are no bars, or if it says “No service,” try moving to a different location. If you’re
indoors, try going outdoors or moving closer to a window.
 Check to make sure you’re in an area with network coverage. Go to your carrier’s
website to see network coverage areas.
 Make sure airplane mode isn’t on. From the Home screen choose Settings, then turn
airplane mode off. If that doesn’t work, turn airplane mode on, wait 15 seconds, then
turn airplane mode off again.
 Make sure to include an area code for every phone number in your contacts list that
you use to send or receive text messages.
 Turn iPhone off and back on again. Press and hold the Sleep/Wake button on top of
iPhone for a few seconds until a red slider appears, then drag the slider. Then press
and hold the Sleep/Wake button until the Apple logo appears. Tap Unlock and enter
your SIM’s PIN if the SIM is locked.
Note: If you enter the PIN incorrectly three times, you may need to contact your
carrier for a Personal Unlocking Key (PUK) to enable your SIM card again.
 There may be a problem with your wireless service. Call your carrier or go to your
carrier’s website.
 Restore the iPhone software. See “Updating and Restoring iPhone Software” on
page 120.
If iPhone won’t turn on, or if the display freezes or doesn’t respond
 Press and hold the Home button below the screen for at least six seconds, until
the application you were using quits.
 If that doesn’t work, turn iPhone off and turn it on again. Press and hold the Sleep/
Wake button on top of iPhone for a few seconds until a red slider appears, and then
drag the slider. Then press and hold the Sleep/Wake button until the Apple logo
appears.
 If that doesn’t work, reset iPhone. Press and hold both the Sleep/Wake button and
the Home button for at least ten seconds, until the Apple logo appears.