Yealink T42s T48s can't upgrade firmware from 66.83.0.55

[peter_sgc]

Hello,

I have 8 T42s Phones and 2 T48s phones, all running firmware 66.83.0.55
3CX says the firmware is out-of-date and won't provision the phones on this firmware.

We have tried to upgrade the firmware, but the phone just reboots back to the same 66.83.0.55

We have tried to go up a single release, down a single release.
The odd thing is that the yealink website doesn't list 66.83.0.55.
It's as if that firmware never existed...

[I would have posted this in the Yealink Phone section but I dont have permissions...]

Any Ideas?

 

[SteveITS]

Can you upgrade through the phone web GUI? https://www.3cx.com/docs/phone-firmwares/

Yealink has the 66.86.0.5 version at https://www.yealink.com/en/solution-detail/resource-for-3cx and you could try that first. Or find some other intermediate version. Sometimes if phones are "too old" firmware they can't upgrade directly to the latest. On that page Yealink has an intermediate for the T5 series for example but they list it there because it's required.

If you know version numbers you can change the number in the 3CX download URL. Usually the old versions are still there just not linked.

 

[NicholasP_3CX]

You would also need to ensure that your PBX is on the correct version.
You are using an outdated version of the PBX, which would mean that your SSL certificate is expired and the phone cannot connect and get its firmware. (cant see any information about the PBX on the activation server)

 

[SteveITS]

Eh, details, details...

 

[JohnS_3CX]

You need to look up the manufacturer's knowledge base, they have an article just for this.

 

[peter_sgc]

So we have tried every firmware from the yealink website and it always fails.
We have even tried the TFTP recovery, but the phone always says "File Too Large"

I don't understand how these phones are even running 66.83.0.55 as this is not a firmware on Yealinks website.

It goes;

T46S(T48S,T42S,T41S)-66.81.0.110.rom
T46S(T48S,T42S,T41S)-66.82.0.30.rom

T46S(T48S,T42S,T41S)-66.84.0.125.rom
T46S(T48S,T42S,T41S)-66.85.0.5.rom
T46S(T48S,T42S,T41S)-66.86.0.5.rom

Notice that 66.83 is missing...

 

[JohnS_3CX]

https://support.yealink.com/en/portal/knowledge/show?id=60d47356076300004a007103

 

[peter_sgc]

Perfect! Thank you!