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iPhone Cellular Data Not Working (Fix It Now)

Updated Feb 13, 2026

⚠️ Immediate Fix

4G/5G symbol missing or internet dead? It's likely a carrier settings glitch or failed handshake. Toggle Airplane Mode ON for 10 seconds, then OFF. If that fails, eject and re-insert your SIM card to force a complete tower reconnect.

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Why This Happens

  • Tower Glitch: Your phone is stuck on an old tower ID.
  • SIM Card: Dirty contacts or loose fit.
  • Update Needed: Carrier settings are outdated.

Step-by-Step Fix

  1. Carrier Update Check: Go to Settings > General > About. Wait 10 seconds. If a popup says "Carrier Settings Update", tap Update.
  2. Reset Network Settings: Go to Settings > General > Transfer or Reset > Reset > Reset Network Settings. This wipes WiFi passwords but fixes cell calibration.
  3. Check Cellular Data Options: Go to Settings > Cellular > Cellular Data Options. Ensure "Roaming" is ON if you are traveling. Toggle 5G Auto to 4G/LTE as a test.
  4. Eject SIM: Use a paperclip to pop the SIM tray. Blow into the slot. Re-insert firmly.
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When to Stop

If you see "No SIM" even after cleaning, your SIM card is dead or the reader is broken. You need a new SIM from your carrier store. If "Modem Firmware" is blank in Settings > General > About, your motherboard is damaged.