No call audio despite confirmed capability

[GrapeJuice]

Hi Everyone.
I took delivery of my PinePhone (3GB/32GB) last week.

The installed Manjaro/KDE is great and yet I couldn' get any calls to complete/audio to be heard. I was using an EE sim and read that no-one has recorded any successes with them. I read on the wiki that calls were working with a "3" sim, so i got one and again no audio.

To clarify - The DIP switches are in the correct alignment (ive tried both positions to check this)
              - With both sims, the calls connect to another mobile and this can call, wake up and alert the PinePhone. JUST NO AUDIO on connection.
              - I have confirmed the mic and speaker work, by using the audio recorder to record my voice and YouTube videos play back.
              - I have tried sending and receiving calls with a wired headset/headphones with no audio received/heard.
              - I have installed in both SD card and eMMC: Manjaro with Phosh, Manjaro with KDE, Ubuntu Touch and Mobian.

As the same happens with every OS Distro, i'm tempted to say its not the sims. I "think" they should be working fine! And the Pinephone Wiki confirms they're working in several cases. This points me more towards a hardware problem. But then having confirmed the speaker and mic work, i'm stumped...

Any thoughts? Dud Pinephone or something else?

Regards

GrapeJuice

[gab]

Looks like an hardware problem to me, maybe the I2S connection between the modem and the rest of the motherboard.

The only data contacts between A64 and modem are USB connection for data and I2S connection for audio. All data going in or out of the modem must go over these connections.

source: https://www.pine64.org/2020/01/24/settin...nceptions/