T42S unable to update firmware

[complex1]

(09-29-2022 07:45 PM)oliv Wrote:  I tried to update a T42S from 66.85.0.5 to 66.86.0.15 using web interface.
I followed the steps bellow:

1. download 66.86.0.15.rom file from Yealink web site
2. select downloaded file after clicking over Browse button
3. click over Update button
4. observe a message like Updating firmware over phone's screen

After 15 minutes, I pulled the phone patch cord and replugged it: it restarted with 66.85.0.5 version.

1. Which 66.86.0.x version shall I target first ?
2. Which 66.86.0.x version shall I target after the first one reached ?

Hi,

The steps you are taking are good.
Devices with v85 firmware can be upgraded directly to firmware v86.

After the firmware upgrade is complete, you may want to check that the phone actually has the latest firmware before removing and reconnecting the phone patch cord.

If the phone contains the correct firmware before the restart, the problem lies in a remote firmware update via RPS that provides the device with the older firmware v85 again.