Can't Get Yealink T48G to Work

[superlative]

Hi.

I have a bunch of Yealink phones configured on the 3CX system and they work fine.

I have bought a Yealink T48G IP telephone. This one has a nice large touch screen.

When I access the admin page over the network, and configure the SIP server IP, ID and Password for the account and click Confirm it says "Register Failed".

Here is a screenshot of the setup page:

https://www.dropbox.com/s/e2vaxink4htwhv6/screenshot-yealink.jpg?dl=0

On other Yealink phones I have them setup and they work fine.

Is there something specific for the T48G that I need to change one of the default settings?

Thanks so much for any help. Been driving me crazy.

 

[superlative]

Anyone here? Appears a lot of questions go with no answers here.

 

[CentrexJ]

Anyone here? Appears a lot of questions go with no answers here.

T48G works great with 3CX. Officially supported with V12 in its most recent service packs. I would double check the password and account are correct. Also I would use automatic provisioning it works much better than manual.