The LU500 unit does not connect to the Internet. What is the problem?

• There is no cellular reception. 

• There are no SIM cards inserted in the LU500 unit. 

• The SIM cards are not activated or do not support the data plan. 

• Modems are not plugged in properly into the USB ports inside the LU500 unit. 

• The APN is not configured correctly on the modems.