How to fix Galaxy J7 not recognizing SIM card issue

Today’s troubleshooting article addresses an issue on Galaxy J7 not detecting a SIM card on one of its slots. If you have a Dual SIM Galaxy J7 that can’t seem to recognize a SIM, this post might help.

Problem: Dual SIM Galaxy J7 not recognizing SIM card

My Samsung Galaxy J7 is a dual sim phone. It recognises both sim cards but I only the second slot is registered to the network. To make sure that it wasn’t the sim card I changed the sim cards from one slot to another. I got the same problem. The software is up-to-date, the phone recognises it has a sim card in the first slot irregardless of the network provider but when I attempt to enable the dual sim option, only the secondary slot enables call waiting and call forwarding. When I try to use the sim in the first slot, I get a “not registered to network” message. The IMEI is there but the phone refuses to register any sim card in the first slot on to its network provider network.

Solution: Under the SIM Card Manager section in Settings, there’s an option to allow you to activate Dual SIM functionality. This option is named Dual SIM always on. Make sure that it’s enabled. Here’s how:

  1. Open Settings app.
  2. Tap Connections.
  3. Tap SIM card manager.
  4. Enable Dual SIM always on.

Reset app preferences

If there’s no change and the problem remains, the next step for you is to ensure that all default apps on the device are enabled. Some Android functionalities like Dual SIM needs some core system apps in order to work. If an important system app has been disabled by mistake, it may cause other apps or functionalities to fail. To reset app preferences:


  1. Open Settings app.
  2. Tap Apps.
  3. Tap on More settings at the upper right (three-dot icon).
  4. Select Reset app preferences.
  5. Restart your Galaxy J7 and check for the problem.

Reset network settings

Another good troubleshooting step that you can do in this situation is ensuring that the device has correct network configuration. To do that, you want to clear the current network setup. Here’s how:

  1. From the Home screen, swipe up on an empty spot to open the Apps tray.
  2. Tap Settings > General Management > Reset > Reset network settings.
  3. Tap RESET SETTINGS.
  4. If you have set up a PIN, enter it.
  5. Tap RESET SETTINGS. Once complete, a confirmation window will appear.

When it’s done, the following changes will occur by performing a reset of network settings.

  • Stored Wi-Fi networks will be deleted.
  • Paired Bluetooth devices will be deleted.
  • Background data sync settings will be turned on.
  • Data restrictive settings in applications that were manually turned on/off by the customer will be reset to the default setting.
  • Network selection mode will be set to automatic.

Wipe the device (factory reset)

Lastly, you want to factory reset your J7. This can look drastic but it’s the only way for you to know if the problem is fixable on your level or not. Follow the steps below to wipe the phone:

  1. Remove all Google accounts from the device
  2. Create a backup of your data.
  3. Turn off the device.
  4. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  5. When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
  6. Press the Volume down key several times to highlight ‘wipe data / factory reset’.
  7. Press Power button to select.
  8. Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
  9. Press Power button to select and start the master reset.
  10. When the master reset is complete, ‘Reboot system now’ is highlighted.
  11. Press the Power key to restart the device.

Get Samsung help

Should none of the solutions above help, there must be a coding issue or hardware fault behind the trouble. Visit your local Samsung Service Center for assistance.