There are no status indications or no heartbeat indicator

This could be due to a blown fuse or the device is in an error state. Repower the device and look for the power up indication (5 flashes) within about 30s. If the status LED is not flashing at all then remove the lid and look on the modem module daughterboard for an indicator on or flashing. If there are not indicators on at all on the module daughterboard check the fuse and check that the power supply does not exceed the rated input voltage for the device. If the module LED is on solid but not flashing but then turns off then the device cannot register the SIM on the mobile network (see below). If the device powers on OK and shows the power up indication but nothing else then try another SIM that is known to be working or try the SIM in a phone.