Yealink CPE80, Administrator'S Manual

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Troubleshooting
289
General Issues
Why is the display device black?

Check whether the display device is connected properly to the VC110 all-in-one unit.

Check whether the endpoint is in sleep mode. Press any key on the video conferencing
phone or remote control to resume endpoint operation.

Check whether the display device is in sleep mode or is turned off. Press the power button
on the remote control or on the display device.

Check whether you have selected the correct video input source. You can try to change
video input source.
Why doesn’t the display device display time and date correctly?

If you have configured the endpoint to obtain the time and date from the NTP server
automatically, ensure that SNTP server and time zone are configured correctly in the
endpoint and whether the connection between the endpoint and NTP server is working
properly.

If you have configured the endpoint to obtain the time and date manually, ensure that you
have configured the time and date correctly.
Why doesn’t the remote control work?

Check whether the endpoint is powered on.

Check whether the positive and negative charges of the battery are connected correctly.

Check whether the battery has sufficient power left.

Check whether no special fluorescent or neon signs nearby.
Why does the endpoint fail to call the far site?

Check whether the network of the local site is available.

Check whether the network of the far site is available.

Check whether the far site enables the DND feature.

Check whether the accounts have been registered correctly, and the endpoint uses the
appropriate account to call the far site.

Ensure that the number you are calling is correct.

Check whether the far site rejects your call.

Check whether the firewall blocks the inbound traffics from the other site.

Check whether the far site has already up to maximum call-in limitation.

If the local site is forced to use encryption, ensure that the far site enables encryption too.
For more information on call encryption, refer to
Secure Real-Time Transport Protocol on