This graphic includes the LED icons on the device:
Power
Green Steady: On AC Power
(only lit if powered on; off if connected to power but not powered on)
Green Blinking: On Battery Power
(device should work with no battery if it is on AC power)
Off: No Power
Voicemail
Green Blinking: New Voicemail
Off: No new voicemail
Wi-Fi
Green Steady: Wi-Fi on
Green Flickering: Wi-Fi on, data transferring
(flickering according to the realtime bitrate)
Off: Wi-Fi Off
Information
Green Blinking: Check Web UI – New SMS, Data Balance, SIM issue, etc.
(Blinking period: 2 seconds – On for 1 second, Off for 1 second)
Off: No need to check
Battery
Green Steady: Battery, more than 50%
Yellow Steady: Battery, 20% - 50%
Red Blinking: Battery, less than 20%
(Blinking period: 2 seconds – On for 1 second, Off for 1 second)
Off: Battery needs to be installed or replaced
(Unit will work with AC power without battery installed)
Antenna/Signal Bars
Blue Steady: Strong signal – 3G/4G (HSPA+)
(Antenna and 1, 2, 3, 4, 5 bars)
Green Steady: Strong signal – LTE
(Antenna and 1, 2, 3, 4, 5 bars)
Red Blinking: SIM checking, SIM error or other abnormal status
(0 bars with RED X. Blinking period: 2 seconds – On for 1 second, Off for 1 second.)
Red Steady: No service, Limited Service, Searching 2G/3G/HSPA+/LTE/Femtocell
(0 bars with RED X)
Blue Blinking: In Femtocell, Strong signal
(Antenna and 1, 2, 3, 4, bars. Blinking period: 2 seconds – On for 1 second, Off for 1 second.)