The Windows Phone 8X by HTC may not display signal or the error message 'SIM not detected'. The SIM card icon may also display in the notification bar. This happens when your device is having trouble finding the SIM card.
To fix this issue:
- Make sure your device is on current software version.
- Turn Airplane mode on and then off.
- Remove and replace the SIM tray.
- Before removing the SIM, be sure to power off the device.
- Remove the SIM tray using the SIM ejector tool.
- Remove and replace the SIM onto the SIM tray, be sure that the SIM is properly seated before placing the SIM tray back into the device.
- Check that you have signal in the notification bar at the top of the phone.
- Replace your SIM card. After replacing the SIM card, be sure that it is properly seated onto the SIM tray before placing it back into the device.