Yealink SIP-T48U Getting Started

Recovery Mode on Yealink IP phones
16
For CP960 IP Phones
This section is only applicable to CP960 IP phones.
Procedures:
1. Reconnect the PoE adapter.
2. Long tap the Home touch key when the touch screen prompts “Initializing…” to trigger the recovery
mode.
The IP phone will read and upgrade the firmware from the USB flash drive, and the touch screen
prompts “Firmware Updating”.
When upgrading successfully, the touch screen prompts “Initializing”.
3. If the IP phone fails to upgrade, the LCD screen will indicate the failure. You need to check and make
sure:
 The file system of the USB flash drive should be FAT32.
 The USB flash drive has been successfully connected to the IP phone.
 The resource files are correctly renamed and placed on the USB flash drive.
 Repeat the recovery mode procedures to try again.
The LCD screen prompts “Update failed (-1)” when failing to upgrade:
4. Tap Settings->General to verify the current firmware version after upgrading successfully.
…. Update failed (-1) ….

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