It's my first time here, and much of this is new to me.
Anyways, I have an S21 (Snapdragon) with Multi-CSC? OYN, XAA/XAA/XAA that I use in Singapore. (SM-G991U)
I just learnt that apparently OTA updates are only given after the location of where the device is being used corresponds with the CSC.
What would my options be now, to update my phone? (Being able to have OTA updates would be preferable)
I know of (just learnt):
• Changing CSC via the phone app (using IMEI number). Never tried and I don't know if I'll get an error code. My main concern is that I'll not be able to update if I get firmware for Exynos instead (S21s in Singapore are Exynos), if I even get a Singaporean CSC on there.
• Flashing/ updating using Odin? (Heard it doesn't work anymore for changing CSC? I have One UI 3.1)
• Updating using ADB?
I'd love to learn something about this whole CSC mess too so I can understand what's happening and how everything works. And if it's not possible to get OTA updates, the best way to update my phone then. Thanks
mavcyh said:
It's my first time here, and much of this is new to me.
Anyways, I have an S21 (Snapdragon) with Multi-CSC? OYN, XAA/XAA/XAA that I use in Singapore. (SM-G991U)
I just learnt that apparently OTA updates are only given after the location of where the device is being used corresponds with the CSC.
What would my options be now, to update my phone? (Being able to have OTA updates would be preferable)
I know of (just learnt):
• Changing CSC via the phone app (using IMEI number). Never tried and I don't know if I'll get an error code. My main concern is that I'll not be able to update if I get firmware for Exynos instead (S21s in Singapore are Exynos), if I even get a Singaporean CSC on there.
• Flashing/ updating using Odin? (Heard it doesn't work anymore for changing CSC? I have One UI 3.1)
• Updating using ADB?
I'd love to learn something about this whole CSC mess too so I can understand what's happening and how everything works. And if it's not possible to get OTA updates, the best way to update my phone then. Thanks
Click to expand...
Click to collapse
Hi Mate
OTA are strictly Active CSC related , independent of the country you are using the phone. I have Spanish active CSC and i get the OTA in Panama
So you will get a new OTA as soon as available , the latest for you CSC (XAA) firmware is:
Date
Version
2021-06-27
11
PDA
CSC
G991U1UEU4AUF5
G991U1OYM4AUF5
https://www.sammobile.com/samsung/galaxy-s21/firmware/SM-G991U1/XAA/download/G991U1UEU4AUF5/1557396/
https://www.sammobile.com/samsung/galaxy-s21/firmware/SM-G991U1/XAA/download/G991U1UEU4AUF5/1557396/
You can change the CSC but it will depend in what firmware you have and what CSC available that firmware has.
To your questions
1 You will not get an Exynos firmware in your phone as you can not force an exynos CSC into an Snapdragon , Singapore does not have Snapdragon firmware , so you can not force a Singapore CSC into your phone
2 Flashing new firmware does not change the CSC anymore ( in my case did not)
3 Update with ADB ? not sure what you mean but if you mean firmware , no is not possible
MAX 404 said:
Hi Mate
OTA are strictly Active CSC related , independent of the country you are using the phone. I have Spanish active CSC and i get the OTA in Panama
So you will get a new OTA as soon as available , the latest for you CSC (XAA) firmware is:
Date
Version
2021-06-27
11
PDA
CSC
G991U1UEU4AUF5
G991U1OYM4AUF5
https://www.sammobile.com/samsung/galaxy-s21/firmware/SM-G991U1/XAA/download/G991U1UEU4AUF5/1557396/
https://www.sammobile.com/samsung/galaxy-s21/firmware/SM-G991U1/XAA/download/G991U1UEU4AUF5/1557396/
You can change the CSC but it will depend in what firmware you have and what CSC available that firmware has.
To your questions
1 You will not get an Exynos firmware in your phone as you can not force an exynos CSC into an Snapdragon , Singapore does not have Snapdragon firmware , so you can not force a Singapore CSC into your phone
2 Flashing new firmware does not change the CSC anymore ( in my case did not)
3 Update with ADB ? not sure what you mean but if you mean firmware , no is not possible
Click to expand...
Click to collapse
Thanks for the reply. Problem is, I've constantly checked for updates but I'm still stuck on the February patch which should actually have even came preinstalled on the phone. (basically, I've not received a single OTA update). This has led me to believe that the country you use your phone in affects receiving OTA updates.
I doubt there's other reasons why I wouldn't receive the updates (since other people have said that location/ connecting to the telco network? affects OTA updates).
Anyways, so to clarify, my only options to update then would be to use:
• Smart Switch (holding off because it is disabled from an app having device ownership)
• ADB (sideloading OTA update)
• Odin (unfamiliar with its uses)
I'm just looking for the path of least resistance to get my phone updated right now. And just to confirm, updating/ flashing (are they the same?) software will not wipe my phone?
Thanks.
mavcyh said:
Thanks for the reply. Problem is, I've constantly checked for updates but I'm still stuck on the February patch which should actually have even came preinstalled on the phone. (basically, I've not received a single OTA update). This has led me to believe that the country you use your phone in affects receiving OTA updates.
I doubt there's other reasons why I wouldn't receive the updates (since other people have said that location/ connecting to the telco network? affects OTA updates).
Anyways, so to clarify, my only options to update then would be to use:
• Smart Switch (holding off because it is disabled from an app having device ownership)
• ADB (sideloading OTA update)
• Odin (unfamiliar with its uses)
I'm just looking for the path of least resistance to get my phone updated right now. And just to confirm, updating/ flashing (are they the same?) software will not wipe my phone?
Thanks.
Click to expand...
Click to collapse
Hi
Is hard to say what really going on , as i said I have an active CSC from one country and live in another and get the OTA with no problem ( lot of people do)
Easiest option for me would be doing updates manually with odin , download the correct firmware and flash using the home-csc file , that way the phone will not be wipe , will be like a regular OTA
Check this threads , here and here even if the thread talks about an exynos the procedure is still valid for a snapdragon
I still dont get OTAs. I flahed BTU, PHE and OXD but nothing. anyone else facing this?
I flahed with odin.
Related
I live in latin america, but I received as a gift an european ace. My question is if I will receive updates from kies over here or I have no other choice but to flash my phone if I want gingerbread? I'm asking because I think my firmware is old (KAA) but there is not any update avaliable.
Thanks.
Read this*, and install this** to upgrade to GB!
* Root the phone
** Flash!
Thanks for the answer but that is not what I'm asking. I want to know if kies will let me update my phone when I'm not (and never will) in the area where it was purchased. I prefer an "official" update if there is a chance of it. If it is not, of course I will flash my phone.
The linked ROM is the official firmware, and since ive never used KIES (never had to), i have no clue.
you must specify a CSC which is for your region (latin america).
You can flash a multi-csc firmware from samfirmware and when done, enter
*#272*YOUR-IMEI# then choose the approriate CSC (latin america)
When done, KIES will update your firmware again.
Cheers
Hi all
I have been wondering how I can tell if the custom or claimed-to-be-official S2 ICS rom supports OTA upgrade?
I know it's perhaps impossible for those custom ones, but the ones I downloaded and flashed that claim 'official', how can I be sure if they supports OTA or not? I am a bit tired of keeping flashing the new versions after all.
Thank you!
it is strictly connected to your product code and region the ROM was released for - these two things have to match.
You will have OTA update if you're using ROM officially released for the region you have set in your phone. and you will get OTA updates only to other ROMs released for this region. few examples:
1. you have XEO product code and you use ROM officially released for XEO - you will get OTA updates but only to other ROMs released for XEO;
2. you have TWO product code but you have installed ROM released for XEO - you won't have OTA update at all (unless you change your PC according to you ROM release region - to XEO - and then, again, updates will be only to XEO ROMs)
3. you HAD XEO and ROM released for XEO, but for some reason you changed your PC to TWO - you won't have OTA update at all (unless you match your PC with region your ROM was released for again).
so, check your product code and the region your ROM was released for, match them however you want - change ROM or PC - and you will be having OTA updates. remember that changing PC is wiping all your data so do backup.
other thing is that you won't have OTA update if you use custom ROM, custom kernel or in some cases root (depending on the root method. rooting phone without making changes to kernel doesn't stop your device from getting OTA update until you make changes in your system).
gaeilge said:
it is strictly connected to your product code and region the ROM was released for - these two things have to match.
You will have OTA update if you're using ROM officially released for the region you have set in your phone. and you will get OTA updates only to other ROMs released for this region. few examples:
1. you have XEO product code and you use ROM officially released for XEO - you will get OTA updates but only to other ROMs released for XEO;
2. you have TWO product code but you have installed ROM released for XEO - you won't have OTA update at all (unless you change your PC according to you ROM release region - to XEO - and then, again, updates will be only to XEO ROMs)
3. you HAD XEO and ROM released for XEO, but for some reason you changed your PC to TWO - you won't have OTA update at all (unless you match your PC with region your ROM was released for again).
so, check your product code and the region your ROM was released for, match them however you want - change ROM or PC - and you will be having OTA updates. remember that changing PC is wiping all your data so do backup.
other thing is that you won't have OTA update if you use custom ROM, custom kernel or in some cases root (depending on the root method. rooting phone without making changes to kernel doesn't stop your device from getting OTA update until you make changes in your system).
Click to expand...
Click to collapse
Thanks for the detailed response. So I guess I need to get a stock rom for Australia then as I bought the phone and am using it in Australia.
Where I can find it? What's the code for Australia market? XEO is just for Euro, rite?
Thanks!!
Get the PC version of Checkfus (search for it on here/Google) & download I9100XWLP8/I9100XSALP4/I9100XXLPS/I9100XWLP8 which is an unbranded Australian ICS stock rom. Flash it following the instructions in this thread. You can also download carrier branded ICS stock roms with Checkfus if that's your preference.
MistahBungle said:
Get the PC version of Checkfus (search for it on here/Google) & download I9100XWLP8/I9100XSALP4/I9100XXLPS/I9100XWLP8 which is an unbranded Australian ICS stock rom. Flash it following the instructions in this thread. You can also download carrier branded ICS stock roms with Checkfus if that's your preference.
Click to expand...
Click to collapse
Thanks!
a few more questions:
1. How can I tell a ROM definitely supports OTA before I install it?
2. How can change my s2 region code to match the ROM's in order to get OTA working again?
3. what's the real difference between carrier branded rom and unbranded ones? e.g. is it better to use say telstra branded rom?
1. Be sure that ROM was released for the region/carrier which fits product code set in your phone - it's always written in ROM info on any download page I know. you may also adapt product code in your phone later, to fit the ROM you wish to use (in case you insist on FOTA/Kies updates).
2. *#272*IMEI# changes your product code. Remember that it wipes all your data.
3. Branded FW may include additional apps but also lot of operator's useless trash. Personally I never use branded ROMs and always suggest debranding. Check thread about chosen ROM for more info.
Sent from my GT-I9100 using Tapatalk 2
gaeilge said:
1. Be sure that ROM was released for the region/carrier which fits product code set in your phone - it's always written in ROM info on any download page I know. you may also adapt product code in your phone later, to fit the ROM you wish to use (in case you insist on FOTA/Kies updates).
2. *#272*IMEI# changes your product code. Remember that it wipes all your data.
3. Branded FW may include additional apps but also lot of operator's useless trash. Personally I never use branded ROMs and always suggest debranding. Check thread about chosen ROM for more info.
Sent from my GT-I9100 using Tapatalk 2
Click to expand...
Click to collapse
Thanks, Re #2, it seems strange that although I never used that command to change my code, only flashed a stock rom issued for another region a while ago, now the checkfus says my handset's the regional code that fits this new rom, other than the supposed-to-be australian one.
Is this normal? So the flashing process can actually alter the phone prod. region code without warning me?
Theoretically it shouldn't but s... happens. If you were flashing ROMs in which your product code wasn't available then it could adjust itself. Mostly I've seen situations when after such an ROM update, PC just wasn't available for change but it stayed the same as it was. On the second hand I've also heard about few cases like yours. Anyway, are you sure about your original PC if you never used this code option? Maybe originally it was different than you think it ought to be?
Sent from my GT-I9100 using Tapatalk 2
You can also try www.sammobile.com for stock firmware. Just make sure that you input your device and region correctly
Edit : and you'll have to flash through odin
Sent from my GT-I9100 using xda premium
gaeilge said:
Theoretically it shouldn't but s... happens. If you were flashing ROMs in which your product code wasn't available then it could adjust itself. Mostly I've seen situations when after such an ROM update, PC just wasn't available for change but it stayed the same as it was. On the second hand I've also heard about few cases like yours. Anyway, are you sure about your original PC if you never used this code option? Maybe originally it was different than you think it ought to be?
Sent from my GT-I9100 using Tapatalk 2
Click to expand...
Click to collapse
Strange!
1. I use *#1234# command and found my rom info is I9100ZSLPG, which is for the region Hongkong - TGY
2. then I use *#272*imei#* (Product code) to check my phone's current CSC, which is shown already 'TGY'.
Now my question is, why my phone still can't get any OTA update?
Any other bit not matched? How to check if any?
Thanks.
I apologize if this is a stupid question since there are several threads about flashing different firmware.. Having not had a Samsung phone since S7 Edge, the process seems to have changed a bit. I bought a Verizon S9+ from a family member for cheap and I'm currently a subscriber on T-mobile. I'd like to flash over to the T-mobile firmware.
Current Baseband is G965USQU1ARB6
I believe this means that I'm on the v1 bootloader.
My understanding is I need to flash to the U1/unlocked firmware without a SIM and then flash to the T-mobile firmware after that. Correct?
Any rationale to picking a specific firmware since it appears there have been several updates since my current one? I assume once I get T-mobile on there I would get OTA updates via T-mobile from then on, correct?
Also, when I switch to T-mobile will I be able to get on the 600 Mhz Band 71 for T-mobile's LTE or are the radios actually different in the different carrier versions of the phone?
Thanks in advance for any help, and I'm sorry again if this is a stupid question - just having a hard time with the changes in firmware flashing that occurred after S8 came out apparently ://
The radios are identical between all U and U1 models, but the firmware isn't. You will find a Verizon phone won't work on TMB without flashing for several reasons (wrong APN which isn't editable, for one).
The latest U1 build is ARF4. That's also available as a U build for TMB. Flash to the U1 then to U. Use normal CSC so it will factory reset both times. You'll be golden.
If you want to be able to switch again, I recommend you block any updates TMB pushes once you're back on U, as newer U builds update the bootloader and you won't be able to flash back to U1 until it gets updated.
Good luck.
CrazyApe18 said:
The radios are identical between all U and U1 models, but the firmware isn't. You will find a Verizon phone won't work on TMB without flashing for several reasons (wrong APN which isn't editable, for one).
The latest U1 build is ARF4. That's also available as a U build for TMB. Flash to the U1 then to U. Use normal CSC so it will factory reset both times. You'll be golden.
If you want to be able to switch again, I recommend you block any updates TMB pushes once you're back on U, as newer U builds update the bootloader and you won't be able to flash back to U1 until it gets updated.
Good luck.
Click to expand...
Click to collapse
Thanks for the reply! I flashed the U1 firmware and used normal CSC to factory reset. Then I flashed the TMB one. When I boot up it still says Verizon and the software version says VZW/VZW/VZW still. Should I have inserted the TMB sim prior to the second flash? Did I hose myself now that I've flashed the latest version and its still VZW? Thanks
kjdBonez said:
Thanks for the reply! I flashed the U1 firmware and used normal CSC to factory reset. Then I flashed the TMB one. When I boot up it still says Verizon and the software version says VZW/VZW/VZW still. Should I have inserted the TMB sim prior to the second flash? Did I hose myself now that I've flashed the latest version and its still VZW? Thanks
Click to expand...
Click to collapse
If you took TMBs newest OTA, you're screwed. You'll have to wait for an updated U1 build. No one knows when that may arrive.
Hello everyone,
I have a south Korea:
Device spec:
S9 plus G965M with Exynos 9810 and says SK Telecom in the start but I think it's unlocked because I have my Portuguese sim card inside and it's working here in Portugal
Band name Ron : G965N KSU 1ARJ1
This
I've went thru a lot of threads but I got flooded with so many information that I'm afraid of the steps to do.
Main goal:
1. Use the phone in Europe / Portugal
2. Change the ROM because even with reset and English chosen, Android has a lot of menus in Korean
3. Even boot loader for Odin is Korean.
4. Install Android pie 9.0 and continue to receive updates. This phone is stopped in October patch. I think it won't update unless I put a Korean sim
Since the current official ROM 9.0 with oneUI and Pie is for 965F and not 965N (mine), and since N partition is smaller, where should I start or how?
10. Should I start with CSC change? Will that change partition also? To what CSC then?
11. Root? TWRP? Custom ROM?
12. I don't care about Samsung pay, but will I lose VoltLTE?
Thanks a lot for your time.
Hi folks,,,
At first excuse my language just plz try to keep up with me to get help
So I bought an used S9 plus Duos, inside its G965F...software info, build number its also G965F,, outside on the back G965F made in Vietnam,,, i discovered that's there is root and its on February security patch i tried to unroot it using Odin,,,the where i discovered its G965N!!!! Tried to continue by downloading official g965N firmware (pie 9) ... when the device restarted after using odin the phone working or showing just one sim even it was working just fine and even I used pie firmware its went back to oreo!!!
Plz ... Biiiig plz I need advices and solutions,,, I want to clean the root, I want to get updates ... and I want to get both of sim 1 and sim 2 work
Vapochilled said:
Hello everyone,
I have a south Korea:
Device spec:
S9 plus G965M with Exynos 9810 and says SK Telecom in the start but I think it's unlocked because I have my Portuguese sim card inside and it's working here in Portugal
Band name Ron : G965N KSU 1ARJ1
This
I've went thru a lot of threads but I got flooded with so many information that I'm afraid of the steps to do.
Main goal:
1. Use the phone in Europe / Portugal
2. Change the ROM because even with reset and English chosen, Android has a lot of menus in Korean
3. Even boot loader for Odin is Korean.
4. Install Android pie 9.0 and continue to receive updates. This phone is stopped in October patch. I think it won't update unless I put a Korean sim
Since the current official ROM 9.0 with oneUI and Pie is for 965F and not 965N (mine), and since N partition is smaller, where should I start or how?
10. Should I start with CSC change? Will that change partition also? To what CSC then?
11. Root? TWRP? Custom ROM?
12. I don't care about Samsung pay, but will I lose VoltLTE?
Thanks a lot for your time.
Click to expand...
Click to collapse
1: cool, super easy and it sounds like you got it taken care of anyways
2: it’s a Exynos processor, so you should be able to root it and throw whatever ROM you want on it
3: if it’s a Korean model it should accept a G965F firmware flash in Odin which isnt a korean bootloader, and even if its not compatible, Odin will just fail out on the flash unless you have the modded version of Odin that is designed to ignore version mismatch errors and flash anyways
4: manually update it with Odin and don’t fiddle with the carrier specific needs for updates
What happened to 5 through 9?? (kidding, I can read between the lines)
10: CSC stands for country specific product code, or something like that. It tells the phone what market it is supposed to be intended for
11: sure, if you want, but youll trip knox if you do. sure. if youd like to, youre welcome to do that
12: SPay can be wonky depending on your CSC, but voLTE is a firmware/carrier specific. I have a regular S9 that i purchased from Cricket (united states MVNO carrier) and it had voLTE when i got it, but i flashed the G960U1 firmware (the "U1" iteration is the snapdragon unbranded version) and voLTE and WiFi calling are now both gone from my menu
---------- Post added at 10:31 AM ---------- Previous post was at 09:46 AM ----------
oh, and youre not gonna change the partition size to anything bigger than it came with. When you Odin flash the firmware, it wont change the amount of internal storage available unless you inadvertently shrunk it with a firmware flash of a smaller storage base phone, which seems unlikely. This was more common in the standard 16gb internal storage days. If the internal storage amnt is incorrect after a firmware flash, factory reset it in stock recovery and that should correct the issue
Hesni said:
Hi folks,,,
At first excuse my language just plz try to keep up with me to get help
So I bought an used S9 plus Duos, inside its G965F...software info, build number its also G965F,, outside on the back G965F made in Vietnam,,, i discovered that's there is root and its on February security patch i tried to unroot it using Odin,,,the where i discovered its G965N!!!! Tried to continue by downloading official g965N firmware (pie 9) ... when the device restarted after using odin the phone working or showing just one sim even it was working just fine and even I used pie firmware its went back to oreo!!!
Plz ... Biiiig plz I need advices and solutions,,, I want to clean the root, I want to get updates ... and I want to get both of sim 1 and sim 2 work
Click to expand...
Click to collapse
I am suffering the same now... did u find the silution then? Pls help me bro
I.zubair said:
I am suffering the same now... did u find the silution then? Pls help me bro
Click to expand...
Click to collapse
Hello!
Im sorry to tell you that a I didnt find solution ?
Hi Everyone,
Can anyone help me with process for flashing UK version firmware of XQ-BC52 on Taiwan version of XQ-BC72. I need to know which firmware files such as ".ta" or any other files to be removed from firmware folder before flashing. The UK or US customization versions supports volte and Wifi calling in my country.
Currently the Taiwan firmware version is at 61.0.A.23.20 (android 11) and UK firmware version is at 61.1.A.2.211 (android 12)
Can I just flash the .oem files of UK firmware to TW firmware?. But, since device firmware versions are different, flashing may fail and corrupt the device. Can you confirm if this is safe to flash?.
Request your help!
ralf_waldo said:
Hi Everyone,
Can anyone help me with process for flashing UK version firmware of XQ-BC52 on Taiwan version of XQ-BC72. I need to know which firmware files such as ".ta" or any other files to be removed from firmware folder before flashing. The UK or US customization versions supports volte and Wifi calling in my country.
Currently the Taiwan firmware version is at 61.0.A.23.20 (android 11) and UK firmware version is at 61.1.A.2.211 (android 12)
Can I just flash the .oem files of UK firmware to TW firmware?. But, since device firmware versions are different, flashing may fail and corrupt the device. Can you confirm if this is safe to flash?.
Request your help!
Click to expand...
Click to collapse
I think yes but r u sure that customized UK fw supports voLTE and WIFI calling? the switches are in the settings? because I have the same model but with eea customized and have no volte or/and vowifi switches.... My carrier supports them btw
I've been told the customised SEA also has Volte and VoWifi wnabled, but I never got any joy out of it when I flashed it into my HK BC72 device. I have tried the previous firmware revision of the UK one, but nothing there either.
Ndlelex said:
I've been told the customised SEA also has Volte and VoWifi wnabled, but I never got any joy out of it when I flashed it into my HK BC72 device. I have tried the previous firmware revision of the UK one, but nothing there either.
Click to expand...
Click to collapse
So if I flash it to my XQ-BC52 will it affect anything? I don't want to lose anything, but I want to use volte I have no idea why it isn't enabled when all of the carriers on my country support it
I would first update it to the newest TW Firmware and check if it works (so you can update, without loosing personal data).
If it still doesn't work, I would try the HK firmware, because of Over-The-Air–Updates (OTA). I have VoLTE and VoWifi in Switzerland with this firmware.
If it still doesn't work, try the BC-52 firmwares (but you loose OTA Updates).
Please just check after flashing a new firmware if you have the functions. If it works, first do a repair with Sony Companion before starting to install everything (like apps, files....). This makes a clean install and avoids a lot potential of failures/problems.
I bought the phone in Etoren and it is the model XQ-BC72, I live in the UK, and the update I received via OTA and is installed is 61.1.A.2.211 release-keys. you shouldn't, I guess Sony recognizes you're in the UK and installs the correct one
LaceeWearsPrada said:
So if I flash it to my XQ-BC52 will it affect anything? I don't want to lose anything, but I want to use volte I have no idea why it isn't enabled when all of the carriers on my country support it
Click to expand...
Click to collapse
You won't lose your data if you explicitly tell it not to clear userdata off your phone, if that's what you mean. If, however, you're referring to certain functionalities I sometime hear of getting lost, then I myself haven't noticed such with all versions of firmware I have tried out so far.
PlatinCH said:
I would first update it to the newest TW Firmware and check if it works (so you can update, without loosing personal data).
If it still doesn't work, I would try the HK firmware, because of Over-The-Air–Updates (OTA). I have VoLTE and VoWifi in Switzerland with this firmware.
If it still doesn't work, try the BC-52 firmwares (but you loose OTA Updates).
Please just check after flashing a new firmware if you have the functions. If it works, first do a repair with Sony Companion before starting to install everything (like apps, files....). This makes a clean install and avoids a lot potential of failures/problems.
Click to expand...
Click to collapse
I've yet to do a clean install, the way you have described it. I guess I'll do it just like that when I've given up on trying to activate VoLTE and VoWifi on my phone. It's interesting that your Hong Kong phone has that function over there. I suppose there is some substance in Sony's insistence that the one's network provider be engaged as well.
I was considering getting the Xperia 1 IV which would be a nice upgrade from my Xperia 1 II but with volte not working it would push me away. I managed to get it working on my Xperia 1 II by simply flashing SEA firmware. It was straight forward and has worked flawlessly with OTA updates. It doesn't look like the Xperia 1 IV will work that way. Even if I was to flash SEA firmware it looks like volte still wouldn't work. Come on Sony sort this problem out