Is there a SIM card reader (behind the blank) on hardware that does not include the cellular module?

[dayveeboi]

Hi, I have an X2 1012 G1 (convertible, 2-in-1) that came from the factory without a Cellular Radio module. Although it did not come with the module, it does have an empty M.2 slot available as well as an opening on the exterior casing where a SIM card reader presumably exists. I have come across this before on another notebook without WWAN that share common parts with one that has mobile broadband  and there was a SIM reader on the mainboard and I am hoping that this is the case.

With the X2 1012 G1 that I am asking about, there is actually a blank fitted. So you are physically unable to put a SIM card  into the slot, where the notebook I previously mentioned did not  (i.e. you could put a sim card in and eject it but it wouldn't do anything without having the WWAN M.2 module and drivers installed).   

You may be wondering why I don't just open it up and look myself or just check the service manual, since I will have to open the machine to install the WWAN antennas and M.2 card anyway. I have tried to open it, and although this device is often praised for its ease of repair/upgradeability (it's the reason I bought this over a surface or some similar 2-in1), I tried to remove the display with my suction cups and the display flexes so severely that I believe that it may have been glued shut, possibly due to a security policy or something similar (I bought it second hand, I have no idea of it's history).

I did check  the service manual, and although WWAN is listed as a possible upgrade, it does not have any mention of  the SIM card reader in the replacement parts list (I already have a compatible WWAN card and antenna, as per the parts list). If I  find out that there is a SIM reader on the mainboard, I will attempt to separate the display assembly from the frame (with heat if required), but I do not want to risk breaking the LCD/Digitizer and find out it is not possible to use the WWAN (outside of trying to find a new mainboard or whatever). 

Thank you very much for reading, as well as for any help or answers you may be able to provide.

David.

(edited for grammar)

[dayveeboi]

Nevermind, after a few weeks of searching on and off (and giving up several times) I got a brainstorm and have solved this question myself. For anyone who comes across this post in the future, the SIM card reader is actually on the same board that the buttons are. There is two separate part numbers and they are indeed different. The part number for the button board that does have a SIM reader is  844876-001.

This does not necessarily mean that the SIM reader will work (although I suspect it does). There is two different part numbers for each variation of mainboard per processor/RAM configuration. One for WWAN, and one without. That may or may not mean anything, since I can not differences in any of the pictures I can find of these mainboards, and the fact that they list different part numbers for mainboards on models that come with windows installed vs those without (although that's likely due to the license being embedded). 

When I get a hold of one of these button/SIM daughter boards I will update this post with the results and let anyone concerned know if this upgrade is indeed possible (without too much headache anyway).