1. From the Main Menu, tap Settings.
2. Verify that Wi-Fi is set to Off or Disabled -- this will ensure that no wi-fi signals are interfering with your Internet access. To take advantage of local wi-fi at a later time, feel free to go back and turn this setting On; just make sure to turn it Off again when you are done using the wi-fi network.
3. Tap General Settings, then tap Network.
4. Turn Data Roaming On -- this will allow your iPhone to locate T-Mobiles data network.
5. If you see a setting for 3G, turn it Off -- the iPhone cannot currently connect to T-Mobiles 3G network, and this setting will interfere with its attempt to connect to our EDGE network for service.
6. Tap Cellular Data Network (this setting may be labeled EDGE instead).
7. In the APN field, enter epc.tmobile.com -- this tells T-Mobile which version of our Internet network you want to connect to. Note: if this does not work, you can try entering in internet2.voicestream.com instead.
8. Leave the Username and Password fields blank -- T-Mobile will assign this information based on your SIM card information.
9. Return to the Main Menu and open Safari to browse the Internet.
IF THIS FAILS, you receive a message like GPRS Not Subscribed, Could Not Activate Cellular Data Network, or the E is missing above:
1. Return to Settings, then tap General, then tap Reset.
2. Select Reset Network Settings (DO NOT reset any other settings. This may relock your device). Your iPhone will turn off, and then turn on again. Please follow the internet setup above.
Let me know if you have issues.