iPhone 4S displays 'No Service' or 'No SIM Card Installed'

Products Affected

iPhone 4S

Symptoms

In certain situations, iPhone 4S may have difficulty recognizing a micro-SIM card, resulting in the following behaviors:

  • "Invalid SIM" or "No SIM Card installed" alert appears intermittently.
  • Status bar displays "No Service" or "Searching" in a location with good network coverage.

Resolution

If you encounter any of the above symptoms on your iPhone 4S, follow the steps below.

Note: These steps are necessary only if you are experiencing these symptoms on an iPhone 4S.

  1. Back up your user content and settings using iTunes or iCloud. See this article for more information.
  2. Restore your iPhone 4S using iTunes.
  3. After the process is complete, restore your user content and settings from your backup.
  4. To confirm that you've successfully restored, verify that the version is now iOS 5.0.1 (9A406) in Settings > General > About. If the version displayed is iOS 5.0.1 (9A405), repeat steps 2 through 4.

Additional Information

If you continue to see "No Service" intermittently in the status bar, update your carrier settings.

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