T58A - Impossible to flash with Teams firmware

[algas32]

I have 25 Yealink T58A with initial SIP config no more active.Telephony migrated to MS Teams.

Those SIP-T58A are on the latest SIP firmware : T58V(T56A)-58.86.0.160

I download the latest T58A Teams Firmware on the website which is T55(T58V,T56A)-58.15.0.168.


I first try update with one from web interface but update failed (refuses the T55(T58V,T56A)-58.15.0.168.rom file).
Error: "Firmware update failed !" + "Software limit".
Rebbot and still 58.86.0.160.


I tried through recovery mode using USB FAT32 drive with the T55(T58V,T56A)-58.15.0.168.rom file renamed to T58V.rom (following the "Recovery Mode on Yealink IP phones" manual) with error message "Update failed -1". I can't find any help on this message anywhere). It reboots after power off/on and is still stucked on 58.86.0.160

I then tried from recovery again but through the TFTP option. "Error update failed -5" (can't find any help about this error message but on the TFTP server logs can I see "error file too big")

I tried to downgrade to SIP T58V(T56A)-58.86.0.20.rom from web interface but it didn't work (again update failed error : "software limit". From an USB KEY, again "Update failed -1".

Same with the T58V(T56A)-58.15.0.26 which should able the transition from SIP to TEAMS as mentionned in your knownledge base.

I've read that .rom file with recovery should be copied together with a .bin and rfs. file I can't find anywhere (your manual also says that 58.86 firmware don't need).


Stucked, I need help