Zte Z791 User Manual page 147

Problem
Echo or
noise
Unable to
select
certain
features
Battery not
charging
Possible causes
You are too far away
from a base station for
your service provider.
Poor network link quality
on the part of your
service provider.
Poor local telephone line
quality.
Your service provider
does not support these
features, or you have not
applied for services that
provide these features.
The battery or battery
charger is damaged.
Possible solution
You can request a
service area map from
your service provider.
End the call and dial
again. You may be
switched to a
better-quality network
link or phone line.
End the call and dial
again. You may be
switched to a
better-quality network
link or phone line.
Contact your service
provider.
Contact the dealer.
147