cannot upgrade or downgrade from x.83.0.55 firmware

[complex1]

(10-23-2019 03:36 PM)kenhoosen Wrote:  We are using 3CX and have recently updated 3CX to version 16. We have several Yealink phones that are on version x.83.0.55 firmware and 3CX states that this version is unsupported. When I attempt to update the phones to a more current firmware, I get a firmware update failed message. To troubleshoot the issue, I have tried both upgrading and downgrading the firmware but, it fails every time. Phone models that we have this issue with are T41S and T21P_E2.

Anyone else have this issue (and possibly a solution)?

Thanks.

Hi,

What you can try is to download the firmware from the 3CX site and do a manual update into the phone(s).
The 3CX supported firmware can be download from here:
https://www.3cx.com/support/phone-firmwares/

Please do not forget to reset the phone to factory default, by long press the OK button, after you have upgraded the phones.

Hope this will help.