Yealink T40G Administrator's Guide

Troubleshooting
581
Firmware and Upgrading Issues
Fail to upgrade the phone firmware
Do one of the following:
 Ensure that the target firmware is not the same as the current firmware.
 Ensure that the target firmware is applicable to the IP phone model.
 Ensure that the current or the target firmware is not protected.
 Ensure that the power is on and the network is available in the process of upgrading.
 Ensure that the web browser is not closed or refreshed when upgrading firmware via web user
interface.
Verifying the firmware generation and phone version
Press the OK/√ key when the IP phone is idle to check the firmware version. For example: 28.82.0.20.
Item
Description
1
28
Firmware ID.
The firmware ID for each IP phone model is:
 70: T54S/T52S
 35: T48G
 28: T46G
 66: T48S/T46S/T42S/T41S
 29: T42G
 36: T41P
 54: T40P
 76: T40G
 46: T29G
 45: T27P
 69: T27G
 44: T23P/G

Yealink T40G Specifications

General

SIP Accounts	3
Wall Mountable	Yes
Opus Codec	No
Display	2.3 inch 132x64-pixel graphical LCD
Network	Dual-port Gigabit Ethernet
PoE	Yes
Headset Support	Yes, RJ9 port
Power Adapter	Optional
Voice Codecs	G.722, G.711(A/μ), G.729AB, G.726
Local Phonebook	1000 entries