Specifications

iPhone 4 Symptom Charts — Connectivity Issues 65
2012-02-21
Deep Dive
Check Result Action
1. Identify carrier type.
Identify whether the carrier
uses CDMA or GSM.
Is the device running on a
CDMA or GSM network?
CDMA Go to step 2.
GSM Go to step 3.
2. Contact cellular carrier.
Contact the carrier to update
the Preferred Roaming List and
verify that the account is active.
Is the cellular issue resolved?
Yes Issue resolved.
No Go to step 5.
3. Reseat SIM card.
Using the SIM removal tool,
eject the SIM card tray and
reseat the SIM card.
Is the cellular issue resolved?
Yes Issue resolved.
No Go to step 4.
4. Test known-good SIM card.
Substitute a known-good SIM
card.
Is the cellular issue resolved?
Yes Issue resolved.
No Go to step 5.
5. Reset network settings.
Go to Settings > General >
Reset > Reset Network Settings.
Warning: This will erase all
stored Wi-Fi passwords.
Is the cellular issue resolved?
Yes Issue resolved.
No Go to step 6.
6. Erase all content and settings.
Go to Settings > General >
Reset > Erase All Content and
Settings.
Warning: This will delete all
user data on the device.
Is the cellular issue resolved?
Yes Issue resolved.
No Go to step 7.