iPhone Not Detecting SIM Card

 Problem: The device shows "No SIM" or "Invalid SIM."

Solution:

1. Reinsert the SIM:

   • Remove and reinsert the SIM card carefully.

2. Restart iPhone:

   • Reboot the device to refresh SIM detection.

3. Check for Carrier Settings Update:

   • Go to Settings > General > About to check for updates.

4. Test with Another SIM:

   • Insert a different SIM card to see if the issue is with the card or phone.

5. Contact Carrier:

   • If the SIM is faulty, request a replacement.