S20 USER GUIDE
11
Ensure the SIM card has enough balance.
SIM card should have GPRS data plan for platform tracking.
Ensure PIN code has been closed.
Authorization SOS numbers can’t work well if SIM card doesn’t have caller ID service. E.g.:
device can’t reply SMS to authorization SOS number because SIM card can’t identify incoming
call.
Turn off device before SIM card installation.
Unscrew and open the rear cover case