The GPS LEDs can indicate different things. Below is a list of what the different flashes mean:
Green LED
Slow and long flashes = Searching for GSM networks
Flashes once every 3 seconds = connected to the GSM network
Flashes twice every 3 seconds = connected to the GPRS network
Lights up steadily = no or incorrect SIM card
Blue LED
Slow and long flashes = Searching for GPS signal
Flashes once every 3 seconds = The device has GPS signal
Illuminated with steady light = Charging in progress
Not lit = fully charged (if USB cable is connected) or discharged