UAC function on EG25-G module

Hello, I bought a module from a Quectel partner. It should have had 4G, voice capabilities and GNSS but the GNSS has been removed/disabled and the voice function doesn’t work when used with AT commands with MINICOM on Linux. The only thing that works is 4G data connection.
Some ICs are missing from the boards I received. I was told that one should be an audio codec but it looks like something else to me, like an USB switch.
This is a picture showing it.

Now, I was wondering if I can still make calls through UAC.
I can send/receive calls and DTMF tones while calling/answering using AT commands but that’s it. No voice can be heard/sent.
Any help would be really appreciated.
Also, there’s a SPDT switch on the side and a push button of which I know nothing about because the producer didn’t send me any guide whatsoever and I have no clue about their correct usage.
It’s a shame as they pretend to be related to your company and, had I not known how they just took one of your reference designs, I would have thought it was Quectel’s fault.
My questions are: Will it work just with UAC (I have yet to try this) ?
Can somebody please tell me what are the missing ICs so that I can add them myself?
Is there the possibility to attach an analog microphone and an analog speaker output directly on the module?

There are so many components missing that I’m actually surprised that It works at all…

Dear 37TS,
Thanks for your inquiry in Quectel forum.
Please note that you should buy module or related product from our official way, not private way.
For missing components, you should contact the supplier to confirm it. We also do not know what components missing.
For this product, it is just like USB dongle which only used for data transmit. Thanks!

I bought from an official reseller but I don’t want to put the name here.
I already talked with them, they said audio codecs are missing.
But I’ve asked precise questions about UAC and analog audio since this is based on a reference design from Quectel.
I removed the metallic cover/heatsink from the module only to take a picture without the IMEI but it says EG25-G GB on it. How can it be only a data card? Is it counterfeit or what?

Please note that what i said is that the board you had in your hand is mainly for data transmit, which means that it is used for internet access. The module support which function not just depend on the software, of course the hardware design also should support. Thanks!
For UAC and analog audio, the module can support, but you should know that if you want to use it, you must to design the corresponding hardware circuit, but it have no such design in your board you used now. So i recommend you to contact and discuss with the board supplier. If you just use our module, and design your own hardware circuit, of course, we can provide you the reference design document. Thanks!

This is wrong. That module can send/receive audio calls with UAC on a computer without any problem whatsoever nor dedicated hardware codec (I’ve wasted one year with articulate solutions for something that can be achieved in 5 minutes). If something is hard to accomplish doesn’t mean that it’s impossible. I can honestly say that the only thing needed is the modem and an USB cable and the board on which it resides is actually almost useless…On the contrary, it’s a security concern as it allows for FOTA and remote mismanagement by third parties…

Hey @37TS I would like to learn more about your experience? I’m also experimenting with a USB board and an EC25 in it. Can you share a bit how you got the UAC functionality into the computer? What were the main challenges?

@Eduar_Tua and/or @37TS , could you please elaborate the USB/UAC solution if you have exchanged messages? I’m struggling with it as well on a linux box with usb connection to EC25-G. Is it possible to get UAC functionality in such a setup with just the USB connection? UAC application guide is not particularly helpful in this sense.