3.5. LED Indicators
The LED indicators described in this section are all single colour LEDs. When the router is powered on, the
power LED is green.
The possible LED states are:
• Off
• Flashing slowly
• Flashing quickly
• On
LED
Status
Description
Booting up
The router takes less than a minute to boot up. During this time, the power LED
flashes.
Other LEDs display different diagnostic patterns during boot up. Booting is complete
when the power LED stops flashing and stays on steady.
Power
On
Power is present
Off
No power. Boot loader does not exist.
Flashing
Booting
Config
On
The router is running a valid configuration file.
Flashing slowly
The router is running in recovery mode (2.5 flashes/second)
Flashing quickly
The router is running in factory configuration (5 flashes/second)
SIM
On
SIM selected and registered on the 3G/4G network
Off
Not selected or SIM not inserted
Flashing
SIM selected and not registered on the network
3G/LTE cellular signal
strength LED
Both LEDs off
Data link not connected or signal strength <=-113 dBm
Left LED on
Right LED off
Data link connected and signal strength <=-89 dBm
Left LED off
Right LED on
Data link connected and signal strength is between -89 to -69 dBm
Both LEDs on
Data link connected and signal strength >-69 dBm
Table 7. LED indicators
Merlin 4400 Series
13
