Firmware upgrade Invalid ROM

[gregory.b]

Hellooo

I would like to get some help
I have a client with multiple Yealink Phone

Most are T31P and T31G

I have some phone model T53 with Firmware 96.86.0.77




I know i should have checked for upgrade but i forgot
Now when i tried to firmware upgrade to 96.87.0.20
it says INVALID ROM .




I did some research and it says sometimes Yealink phone can't jump Firmware like that and need a Bridge Intermediate firmware
I was hoping you could share with me where i could get the version before

i tried also on Yealink official page and the given firmware 97.86.0.15 also doesn't work

I need one version older i think

 

[Charles_3CX]

Hi, the current firmware version is very old and likely needs an intermediate firmware version to be updated manually on the phone. For this, you will need to contact Yealink support directly to assist.