What do the colored LED lights on the MiFi mean?
After some searching, I found the answer! I figure that others might be interested as well:
-LED not lit: No power to modem
-LED Blue (Solid): Modem is on and you’re roaming
-LED Green (Solid): Modem on and fully charged
-LED Green (Blinking): Modem is in hibernate
-LED Red (Blinking): Battery is critically low
-LED Amber (Solid): Charging
-LED Amber (Blinking): Modem error
LED Side Light Indicator--Modem data status:
-LED not lit: No power
-LED Green (Solid): Modem is on, but not transmitting/receiving data
-LED Green (Slow blinking): Modem is on, but no service
-LED Green (Fast blinking): You’re good to go!
(Source: pocketnow.com/thought/chuongs-pick-novatel-mifi-pu... )