Yealink SIP-T48U Getting Started

Recovery Mode on Yealink IP phones
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2. Click OK twice to save the settings.
3. Long press and reconnect the power adapter to trigger the recovery mode.
The W90DM/W90B will download and upgrade the firmware from the TFTP server.
You can view the syslog of the TFTP server to check if the W90DM/W90B downloads the firmware
successfully as shown below:
4. Find the current IP address of the device on the DHCP server in the list of registered DHCP clients.
Using Recovery Mode on Yealink IP Phones
(USB Flash Drive)
This section introduces how to perform recovery mode using USB flash drive on Yealink IP phones step
by step.
For MP54/MP56/MP58/VP59/SIP-T58A/T57W/T54W/
T53W/T53/T48U/T48S/T46U/T46S/T43U/T42U/T42S/T41
S/CP920 IP Phones
This section is only applicable to SIP phone series including MP54, MP56, MP58, CP920, SIP-T41S,
SIP-T42S, SIP-T42U, SIP-T43U, SIP-T46S, SIP-T46U, SIP-T48S, SIP-T48U, SIP-T53, SIP-T53W,
SIP-T54W, SIP-T57W, SIP-T58A, and VP59.
The following procedures take the SIP-T46S IP phone for reference.

Yealink SIP-T48U Specifications

General

Handset type	Wired handset
Product type	IP Phone
Product color	Gray
USB 2.0 ports quantity	USB 2.0 ports have a data transmission speed of 480 Mbps, and are backwards compatible with USB 1.1 ports. You can connect all kinds of peripheral devices to them.
Expansion module support	Yes
Ethernet LAN (RJ-45) ports	2
Display diagonal	7 \
Display resolution	800 x 480 pixels
Lines quantity	- lines
Phonebook capacity	1000 entries
Number of VoIP accounts	16
Voice codecs	AGC, AJB, AMR-WB, CNG, G.711, G.722, G.723.1, G.726, G.729ab, VAD, iLBC
Security algorithms	AES, HTTPS, SRTP, TLS
Ethernet LAN data rates	10, 100, 1000 Mbit/s
Ethernet LAN interface type	Gigabit Ethernet
Front camera	-
AC adapter input voltage	100 - 240 V
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Keypad number of keys	29
Number of handles included	1 pc(s)
Harmonized System (HS) code	85171800

Weight and Dimensions

Width	226 mm
Height	185 mm