Quick Checks

Mobile data failures have a short list of likely causes. Work through these before assuming there's a deeper problem:

  1. Airplane mode is on. Check the status bar — airplane mode icon (airplane symbol) cuts all cellular radio. Swipe down and toggle it off.
  2. Mobile data is toggled off. On iPhone: Settings → Cellular → confirm "Cellular Data" is on. On Android: Settings → Network & Internet → Mobile Network → confirm data is on.
  3. Data Saver / Low Data Mode is on. iPhone: Settings → Cellular → Cellular Data Options → Low Data Mode. Android: Settings → Network → Data Saver. These can restrict background data heavily.
  4. Data limit reached. If you're on a limited data plan, check your carrier app or Settings for current data usage. A reached limit blocks data until the plan resets or you add more.
  5. Restart the phone. Full restart — power off, power on. This resets the cellular modem, which often clears temporary connection issues.

iPhone-Specific Fixes

Reset Network Settings

This clears all network configurations (Wi-Fi passwords, VPN settings, cellular APN settings) and resets them to defaults. It's disruptive (you'll need to re-enter Wi-Fi passwords) but fixes the majority of persistent cellular data issues on iPhone:

Settings → General → Transfer or Reset iPhone → Reset → Reset Network Settings → enter passcode.

Update Carrier Settings

Carrier settings updates (separate from iOS updates) configure APN settings and network parameters for your specific carrier. Settings → General → About → if a carrier update is available, you'll be prompted. Tap "Update."

Remove and Reinsert SIM

A partially seated SIM card causes intermittent cellular issues. Use the SIM tool (or a small paperclip) to eject the SIM tray, remove the SIM, inspect it for damage, and firmly reseat it. For eSIM devices, go to Settings → Cellular → check the eSIM plan is active.

Android-Specific Fixes

Reset Mobile Network Settings

Settings → System → Reset options → Reset Wi-Fi, mobile & Bluetooth. This resets APN settings and network configuration. Path varies by Android manufacturer (Samsung, Google Pixel, etc.) — search Settings for "Reset network."

Check APN Settings

APN (Access Point Name) settings tell the phone how to connect to your carrier's data network. These are usually auto-configured, but can become corrupted. To reset them:

  • Settings → Mobile Network → Access Point Names (or similar path)
  • Tap the three-dot menu → Reset to default
  • If no defaults appear, contact your carrier for the correct APN settings to enter manually

Safe Mode Test

Boot the Android device into Safe Mode (press and hold Power → press and hold "Power off" until "Safe mode" appears). If mobile data works in Safe Mode, a third-party app is interfering. Uninstall recently installed apps to identify the culprit.

When It's a Carrier Issue

Some mobile data problems are on the carrier's side, not the device:

  • Network outage: Check the carrier's status page or DownDetector for reports of outages in your area. Widespread reports = wait for the carrier to resolve it.
  • Account issue: Late payment, suspended account, or a plan change that disrupted service. Log into your carrier's app or website to check account status.
  • SIM deactivated: A SIM that hasn't been used in a long time may be deactivated by the carrier. Contact customer service to reactivate.
  • 5G compatibility: If you recently switched to a 5G plan but your device is 4G-only, you'll connect at 4G speeds. The data will still work — this is a speed issue, not a connectivity issue.

Phone shows bars but no data. This is an APN configuration issue, not a signal issue. The phone can receive the cellular signal but isn't configured to use the data channel properly. Reset network settings or manually check APN settings from your carrier.

We service smartphones and tablets. Network configuration, software issues, and hardware problems — we diagnose mobile devices in-house. Bring in your phone or tablet for a free assessment.