User's Manual

Page 70 of 79
performance of a battery will be
reduced after a few years’ use.
Cannot be
registered to the
network
1.The signal is too weak or there is
interference by surrounding radio. Look
at the signal status on the screen to
make a judgment.
2. Whether the SIM card is installed
properly, or well contacted? Whether
the SIM card is damaged?（Please
contact the network service operator if
the SIM card is damaged）