Cant receive phone calls to GrandStream GXP1620,FW version not supported

[danagt]

Hi, I have added GrandStream GXP1620 to extension and in 3cx admin "Phones" it shows up in red colour: Fw version Not supported 1.0.7.6.
It looks like the lastest version is not supported to complete phone provisioning and I need 1.0.7.3 version instead. I assume IP phone is not provisioned thats why I dont get calls but it goes directly to extension's voicemail. Please advice what to do. Is it possible to downgrade to 1.0.7.3? How difficult it is?

 

[AWS2P]

Yes, latest 3CX supported firmware is 1.0.7.3 so if your phone is at a higher level it may not work properly , to Downgrade phone FW ask on GS forum or support.

 

[Evolute IT]

You can safely downgrade this phone to the supported firmware via 3CX Firmware button. No restrictions were applied on that firmware.

 

[JohnS_3CX]

If the extension shows a red dot, then most likely the provisioning and/or registration failed.

So firstly make sure the device is able to provision after a factory reset by following this:
https://www.3cx.com/sip-phones/grandstream-gxp16-series/

Hint: If it is a STUN phone it should boot up and ask for user/pass after successfully resetting it, this is a good sign