1) Make sure that the device is connected to the antenna and the 4G SIM card is inserted correctly

  2) Please make sure that the SIM card is available and has remaining data (You can try to insert your phone SIM card to the device, which is easy to check whether it is the device's SIM card problem)

  3) Whether the 4G signal at the current location is normal (You can check by using SIM card of the same operator on the mobile phone at the same location)

  4) Whether the device antenna is broken

  5) Please confirm that the power supply of the device is normal (Please use 5V/2A power adapter. Solar-powered 4G devices have strict requirements on power supply, abnormal current and voltage will cause the device to fail to connect to the Internet or even to start up)

  Note: Make judgment based on whether the device's power supply, signal, SIM card data and other status are normal