Yealink SIP-T52S Administrator's Guide

Troubleshooting
991
 If the IP phone is plugged into a power strip, try plugging it directly into a wall outlet.
 If your phone is PoE powered, ensure that you are using a PoE-compliant switch or hub.
Why does the IP phone display “No Service”?
The LCD screen prompts “No Service” message when there is no available SIP account on the IP
phone.
Do one of the following:
 Ensure that an account is actively registered on the IP phone at the path
Menu->Status->More->Accounts.
 Ensure that the SIP account parameters have been configured correctly.
Phone Book Issues
What is the difference between a remote phone book and a local phone
book?
A remote phone book is placed on a server, while a local phone book is placed on the IP phone
flash. A remote phone book can be used by everyone that can access the server, while a local
phone book can only be used by a specific phone. A remote phone book is always used as a
central phone book for a company; each employee can load it to obtain the real-time data from
the same server.
Audio Issues
How to increase or decrease the volume?
Press the volume key to increase or decrease the ringer volume when the IP phone is idle or
ringing, or to adjust the volume of engaged audio device (handset, speakerphone or headset)
when there is an active call in progress.
Why do I get poor sound quality during a call?
If you have poor sound quality/acoustics like intermittent voice, low volume, echo or other
noises, the possible reasons could be:
 Users are seated too far out of recommended microphone range and sound faint, or are
seated too close to sensitive microphones and cause echo.
 Intermittent voice is mainly caused by packet loss, due to network congestion, and jitter,
due to message recombination of transmission or receiving equipment (e.g., timeout
handling, retransmission mechanism, buffer under run).
 Noisy equipment, such as a computer or a fan, may cause voice interference. Turn off any
noisy equipment.
 Line issues can also cause this problem; disconnect the old line and redial the call to

Yealink SIP-T52S Specifications

General

Touchscreen	-
Display diagonal	2.8 \
Backlight display	Yes
Display resolution	320 x 240 pixels
Lines quantity	16 lines
Phonebook capacity	1000 entries
Number of VoIP accounts	12
AC adapter input voltage	100 - 240 V
Bluetooth version	2.1+EDR
Security algorithms	802.1x RADIUS, HTTPS, MD5
Ethernet LAN interface type	Gigabit Ethernet
USB 2.0 ports quantity	1
Ethernet LAN (RJ-45) ports	2
Mounting	Desk/Wall
Handset type	Wired handset
Product type	IP Phone
Product color	Black
Voice codecs	G.722, G.723, G.723.1, G.726, OPUS, iLBC
Volume control	Digital
Operating temperature (T-T)	-10 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Cables included	LAN (RJ-45)
Number of handles included	1 pc(s)
Front camera	No
Operating system installed	Linux

Weight and Dimensions

Depth	212 mm
Width	211.6 mm
Height	166.8 mm