Mod Phone to answer as carrier branded?

[Just_Me]

Is it possible to mod the x3 registry keys so the phone looks like a L950 to the ATT network?
Basically make the phone (and carrier) believe that the phone is branded/locked to the carrier?

 

[Adventurer64]

If you figure it out please post because I'd like to get an X3 on TMo with all bands functioning.

 

[Just_Me]

I got the idea from this thread as it talks about phone diagnostic codes. I know some work across brands, didn't know how HP may have implemented (or not) the carrier branding of the base ROM image.

 

[nate0]

When you say "looks like a L950 to the ATT network" what do you mean in detail by that?

Generally speaking the only thing I know for sure about getting carrier enhanced services on a Windows 10 Mobile phone is that it has half to do with the SW/FW on the device and the other half has to do with the imei matching a branded Windows device that is supported on their network. This is definitely the case with AT&T specifically. It is easy to get the former done on Lumia's and the Idol 4s and then we just call AT&T and ask them to update our IMEI with our sim ID to that of a branded Lumia 950 for AT&T. I did this on the 950 XL and Idol 4s. VoLTE and HD Voice work after Software provisions correctly on the device. I have posted other threads on this as guides but over on XDA (I should copy them over here too if I have not already).

The Elite X3 I figured would be just like the IDOL 4s in how it provisions the keys/settings for VoLTE and HD voice but it was not. HP has some other OEM magic going-on with their device and it does not work as easily as it does on the IDOL 4s. I did not spend tons of time trying to figure out what was different though or how to work around it. So by all means if you do find the answer share it.

I can add this though and remember I am not an HP/Microsoft sw engineer by all means but if you want to go deeper into looking into this you need to unlock the file systems on your phone.
From my viewpoint there are two locations of files that do the provisioning for Carrier support and Radio support on the OS side. There are some directories under C:\Programs\CommonFiles\ that house some or all the carrier provisioning files. There is also on the other OEM devices (like Alcatel/HP/Vaio/MCJ etc.) a couple directories under C:\Windows\System32 named mcfg_hw and mcfg_sw and those house a bunch of dll files for what I believe to be part of the modem\radio configurations and or other sw configs for the phone. These might aid for the phone to supported by whatever carrier sim you are using. There are also Modem configurations located on static/nonvolatile partitions and contain the NVI data and/or other radio info, those partitions are usually labeled as MODEM_FSx (x being usually 1, 2 and C). They cannot be access directly, or at least easily (I have never managed to touch them directly) but on Lumias we can run a thor2 command to update nvi data based on NVI files positioned under C:\Programs\CommonFiles\OEM. This does not work on other OEM devices though since they do not use a UEFI flashing app and other types of built in utilities/tools that thor2.exe can interact with.