[Sony Xperia X Compact Questions & Answers] mcc111:
I had a Sony XPeria X Compact. I loved it. I dropped it and it broke.

I bought a new one on eBay.

The new one came in an original box, shrinkwrapped, with the stickers. So either it is brand new or somebody did a real sneaky job refurbishing. (The battery was at 100% at first open which I found suspicious for a 2016 phone). It was shipped from Hong Kong.

After inserting my SIM, the new one does not connect to cell or Internet.

I believe somehow I have got a Hong Kong SKU, and the Hong Kong firmware is not using North America LTE bands.

The things I notice unusual are:

- The language it suggested on first bootup was Chinese [but there are no China apps, no Baidu, implying Hong Kong]

- It offered to let me set up the fingerprint sensor, I think this was disabled in the USA version(?)

- On boot, shows notification from "WAP Push" app saying "Missing permissions". On tap it says "Allow WAP PUSH to send and view SMS messages?". I think this was set up automatically on first boot in my original phone.

- If I insert SIM and turn on roaming (I selected LTE (preferred)/WCDMA/GSM), I am able to get a status bar saying I am getting cell signal from Rogers Wireless, full bars. However there is no data, attempting to use a webpage gets "You are in offline mode"

- On first boot with SIM I got a SMS from AT&T saying "AT&T FREE MSG: We're sorry, but the phone you recently tried to use will not work on our network. Don't worry, make a call now to any number and it will redirected to an AT&T representative to help you."

- Notifications bar and Quick Settings pane show separate icons for "Mobile Data" and "Data Roaming" which my old XPeria did not (they were one box)

On the Internet, I find many posts suggesting there is no physical difference between different region Xperias, but some say the regional firmware differs. Because of these minor differences between my original USA-purchased XPeria, I think I have a different regional firmware now.

About AT&T

I am assuming the problem with getting cell service is the device. However, the problem might actually be AT&T.

A couple months ago, on my original XPeria X Compact, AT&T shut off my ability to make phone calls. They redirected every call to AT&T customer service. They said my device was not supported.

It turns out AT&T is shutting off 3G as part of the upgrade to 5G, so everyone with a 3G-only phone will have to upgrade. But, AT&T is using this as an excuse to force even people with compatible phones to switch to an AT&T-whitelisted phone. After complaining to the customer service rep, they re-allowed my phone. Later, after my XPeria broke and I was temporarily using a cheap ZTE phone, I went through the exact same process.

The problem I am having with my new XPeria is different from the problem I had with AT&T on my old XPeria and my new ZTE. The previous problem, data worked fine but calls were disabled. Now neither data or calls work. However it is POSSIBLE AT&T is actually the one breaking me.

A weird detail is that I have an AT&T account but I am currently in Canada. I have free Canada roaming so with phones other than this new (Hong Kong?) XPeria, I just turn on roaming and there is no problem.

Things I have tried

I have tried upgrading the OS until there are no more software updates available and then doing a factory reset. After the factory reset it initially guessed USA rather than China for language settings, but the other strange quirks are still there.

There is another thread with a similar question. A reply linked a file "sony-xperia-x-performance-so-04h" on "xperiastockrom" dot com, but it was hosted on Google Drive and none of the twenty or so mirrors seem to work. Google says the "quota" for the file is exceeded.

I have tried the XPeria Companion app. It allows me to select "Software Repair" which I believe is supposed to reinstall the firmware. However, all it does is spend a long time downloading a file, reboot to a blank-screen mode (bootloader?) and print this error

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Software repair error​

An error occurred while repairing your device.

Please try again. If the problem persists, please contact Sony support.

UEGetPhoneInfoMissingInfo

SO-02J 3589 1305-0031 R2E 34.4.A.2.19

2.14.1.0 / Windows 10 64 bit / Win32 / US / F5321 / 34.4.A.2.19

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By doing some REALLY sketchy stuff (downloading Sony's fastboot driver file which is not a driver at all but an inf and which by itself I could not get to work at all, then merging the "Sony Erickson" lines from the Sony INF into the INF from the official Google Android driver, then installing my modded Google driver with driver enforcement off), I was able to talk to the phone in fastboot mode. The device shows up in "fastboot.exe devices". However "fastboot.exe oem device-info" does not work and I don't know what to do in fastboot, because I don't know where to get a stock rom/firmware to install. (EDIT: I got "getvar all" to work, it gave me baseband version 1302-7793_34.4.A.2.85 bootloader version 1299-4841 S1_Boot_MSM8956_LA1.0.1_O_167 and an SN#).

I downloaded Sony's "EMMA" aka Flashtool. If I boot the phone into bootloader mode (start up then hold down down-volume to go to a black screen mode-- light is green in this mode whereas it's blue in fastboot/adb.exe reboot bootloader mode, no idea if this means anything) EMMA is able to detect the F5321 (and it could do this even before I installed my evil hacked fastboot driver). But, it says it can't restore the firmware because the phone is not unlocked and EMMA can only fix an unlocked phone.

What should I do to restore North America cell-data compatibility? It seems like unlock the bootloader then restore with EMMA is my best bet. But I am scared to do that because I am afraid I am doing something irreversible (will unlocking it once set the phone as "tampered"? will it break sony's camera DRM or whatever). If I know it will work and/or that there is no other way tho I will try it.

Note I am not at this time attempting to install a custom ROM. I am just trying to install the most normal Sony OS possible.