Huawei EchoLife HG520b User Manual page 5

Use the accessories such as the power adaptor provided or
authorized only by the manufacturer.
Make sure that the device does not get wet. If water gets into the
device, disconnect the power supply immediately and unplug all the
cables connected to the device, such as the power cable, and then
contact the authorized maintenance center.
The power supply of the device must meet the requirements of the
input voltage of the device.
Before plugging or unplugging any cable, shut down the device and
disconnect the power supply.
While plugging or unplugging any cable, make sure that your hands
are dry.
Do not step on, pull, or stretch any cable. Otherwise, the cable may
get damaged, leading to malfunction of the device.
Do not use old or damaged cables.
Keep the power plug clean and dry, to prevent electric shock or
other dangers.
During lightning, disconnect the device from the power supply, and
unplug all the cables connected to the device, such as the power
cable, telephone cable, to avoid lightning strike.
If the device is not used for a long time, disconnect the power supply
and unplug the power plug.
If smoke, sound, or smell is emitted from the device, stop using the
device immediately, disconnect the power supply, unplug the power
supply and other cables. Contact the authorized maintenance
center for repair.
Make sure that no object (such as metal shavings) enters the device
through the heat dissipation vent.
Do not scratch or abrade the shell of the device. The shed painting
may lead to skin allergy or malfunctions of the device. If the shed
painting material drops into the host, a short circuit may occur.
Cleaning Requirements
Before cleaning the device, stop using it, disconnect the power
supply, and unplug all the cables connected to the device, such as
the power cable, and telephone cable.