Yealink T28 Technical manual

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Safe mode update for Yealink IP Phones
Summary: You may need to follow a safe mode update when the phone has a
problem and cannot boot properly.
Yealink UK provide a TFTP server with the latest FW versions loaded in the
correct format enabling the phone to update from this TFTP server, providing
the phone can reach this location from its current network. The public IP
address for the Yealink UK TFTP server is 178.239.102.107
Alternatively you will need to prepare a local TFTP server, put the required
firmware into the local TFTP server root and rename the firmware to the
correct format, as below. Then enable the phone to update the firmware via
the local TFTP server.
Operation Procedure using the Yealink UK TFTP Server:
1. Press and hold the Speaker button as soon as you power on the phone.
2. A prompt will display on the LCD, requesting for IP Address, Netmask, IP
Gateway and TFTP server. By pressing up/down/left/right navigation keys,
you can move among the fields using the arrow keys. (The values below
are just for reference. Depending on your network environment, you should
specify correct value for each of them) :
4. TFTP Server: 178.239.102.107 is the public IP Address of the YUK
TFTP server.
3. After completing the correct values for your network, press OK button to go
on or press cancel button to quit safe mode. By pressing the OK button, the
phone will go to download the firmware and update, during when it will
show on the LCD: (this may differ on different models)
1. IPAddress: 192.168.0.222
2. Netmask: 255.255.255.0
3. IP Gateway: 192.168.0.1
4. TFTP Server: 178.239.102.107
…Updating…
Please wait…

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4. If it fails, it will show:
Normally this is because the YUK TFTP server cannot be reached. Please
check the connection and settings.
Operation Procedure using a local TFTP Server:
1. Start a local TFTP server. (For example, the server address is
192.168.0.3)
2. Select the required firmware for update. Put it to the TFTP server’s root
directory.
Rename the firmware, following the rule:
t28.rom for T28
t26.rom for T26
t22.rom for T22
t20.rom for T20
t12.rom for T12
T38.bin and T38.rom for T38G (two files are required for the T38G)
Note:
Only the above 6 Yealink models support this kind of safe mode update.
Also the T38 option may take a long time, in excess of 40 minutes to
complete the process, due to the size of the file being transferred.
3. Press and hold the Speaker button as soon as you power on the
phone.
4. A prompt will display on the LCD, requesting for IP Address, Netmask,
IP Gateway and TFTP server. By pressing up/down/left/right navigation
keys, you can move among the fields using the arrow keys. (The
values below are just for reference. Depending on your network
environment, you should specify correct value for each of them) :
…Update fail…
Please reboot
1. IPAddress: 192.168.0.222
2. Netmask: 255.255.255.0
3. IP Gateway: 192.168.0.1
4. TFTP Server: 192.168.0.3

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5. After completing the correct values for your network, press OK button
to go on or press cancel button to quit safe mode. By pressing the OK
button, the phone will go to download the firmware and update, during
when it will show on the LCD: (this may differ on different models)
If it fails, it will show:
Normally this is because that the TFTP server cannot be reached or the
firmware for update is not available or incorrectly named in the TFTP
server. Please check the connection and settings.
Note:
1. Compared to a HTTP or FTP method, the TFTP behaves much slower, so it
may take a longer time (maybe more than 15 minutes) for the entire update
to complete. In the case of the T38 this maybe over 40 minutes.
2. Not all Yealink models support safe mode update. (units shipped after
August 2009 should have this functionality)
3. It needs the firmware support. (The version needs to be higher than
x.41.x.x)
…Update fail…
Please reboot
…Updating…
Please wait…