Yealink T46S Firmware Downgrade

[mbrownbitos]

I have just purchased a new Yealink T46S. It came loaded with firmware 66.9.0.80. According to the provisioning page for this phone it needs a downgrade on the firmware. I have tried to go through the auto provisioning process and it results in a Failed to verify firmware. Manual attempts also result in the same Failed to verify firmware message. I have filed a ticket with Yealink and they are claiming that this firmware version is a SFB only version and additional licenses are needed to be purchased to downgrade the firmware despite it being advertised as supporting SIP accounts. Has anyone been successful in getting this downgraded and configured on 3CX?

 

[Saqqara]

If you look in phone gui, you may find an option to switch it to sip functionality

this should get the phone to work, but you will get 3cx warnings about the firmware which you will have to ignore

 

[complex1]

What you can try is to recovery the firmware of the phone from SfB to SIP, but I am not sure if this will work and in worst case it can brick the phone.
Ask Yealink support and maybe they can help you.