Specifications

iPhone 4 Symptom Charts — Connectivity Issues 68
2012-02-21
7. 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 8.
8. 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 9.
9. Restore with iTunes.
Restore the device using
the latest version of iTunes.
If restore fails, attempt DFU
restore.
Is the cellular issue resolved?
Yes Issue resolved.
No Determine if the issue is caused by
accidental damage. Refer to the Visual
Mechanical Inspection guidelines.
SIM Card Issues
Known-Good Parts & Materials Required: SIM card, SIM removal tool
Note: The iPhone 4 (CDMA model) does not have a SIM card. This information does not apply
to this model of iPhone.
Quick Check
Symptoms Quick Check
• “Invalid SIM card installed.”
message
• “Dierent SIM detected. Please
connect to iTunes.” message
1. SIM alert messages can be caused by inserting a
non-Apple authorized carrier SIM card. Verify that
the SIM card is authorized to be used with this
particular device.
2. SIM alert messages can be caused by inserting a
SIM card that is not the SIM used for the device’s
current activation. For example, if a new SIM was
used to activate the device, but the previous SIM
is later inserted, or a dierent SIM card is inserted,
such as during testing.
3. Restart the device.