Apple iPhone/iPhone 3G (User manual) - Manual (Page 136)

136 Appendix A Troubleshooting
This may occur if you removed the SIM card from iPhone and replace it with another
SIM card.
Safari, Text, Mail, and Contacts
Websites, Text, or Email Aren’t Available
Check the cell signal  icon 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.
If the cellular network is not available, connect to a Wi-Fi network if possible.

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.
Important: 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.
If you’re traveling abroad, you may not have Internet access because Data Roaming

is turned off (the default). Turn Data Roaming on or connect to a Wi-Fi network.
To turn Data Roaming on, in Settings choose General > Network and tap Data
Roaming. Data roaming charges may apply.
Important: Data roaming charges may apply. To avoid data roaming charges, turn
Data Roaming off.
Restore the iPhone software. See “
 Updating and Restoring iPhone Software” on
page 141.
Email Attachment Won’t Open
The file type may not be supported. iPhone supports the following email attachment
file formats: