
I forgot to mention the model number of the phone - I am using T21P E2 and the latest firmware is 52.84.0.125Please provider more info on your setup - https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/
When the phone is provisioned the password is changed under the 'Phone Provisioning' tab the new password is under
View attachment 27502
Click on the eye icon to the right and the password will be displayed
I am using T21P E2 and the latest firmware is 52.84.0.125Hello,
You are currently using older firmware. I highly recommend you read our guide here to help you get started and to install the correct firmware: https://www.3cx.com/sip-phones/yealink-t20p-t22p-t26p-t28p/
Also, kindly read the guide that @Saqqara posted above, then provide us with information so we can better understand how you were trying to provision them in your specific case.
I am using T21P E2 and the latest firmware is 52.84.0.125
I tried with both firmware as an option (52.84.0.35 and 52.84.0.125) both didn't work for me, the .35 is recommended by the 3CX and I downloaded it from the 3cx site but the end result was same.I think you probably missed something (or you were looking at the Yealink site instead of ours).
Please read this guide again and follow the links inside to reach the latest version that 3CX provides
https://www.3cx.com/sip-phones/yealink-t20p-t22p-t26p-t28p/
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