Develop Bugs

can someone please help me?

this may be the dumbest thing i have ever done. and i feel stupid.
so i saw that 8.0.0 was released for the A5 BTU.
i assume mine was BTU because it was unbranded and I bought my phone from Carphone.
i install the firmware, only to know that i have no service. and in settings it shows up a wierd carrier that i cannot access.
so i plug it into smart switch on my pc, and it shows up as XER instead of BTU.
im so confused, can someone please help me? i feel really dumb
(i have left a screenshot of wierd carrier)
my imei and baseband also show up as unknown

YoMarshMellow said:
this may be the dumbest thing i have ever done. and i feel stupid.
so i saw that 8.0.0 was released for the A5 BTU.
i assume mine was BTU because it was unbranded and I bought my phone from Carphone.
i install the firmware, only to know that i have no service. and in settings it shows up a wierd carrier that i cannot access.
so i plug it into smart switch on my pc, and it shows up as XER instead of BTU.
im so confused, can someone please help me? i feel really dumb
(i have left a screenshot of wierd carrier)
my imei and baseband also show up as unknown
Click to expand...
Click to collapse
Same problem here with weird settings app...(A320FL)

Pagan_Serpent said:
Same problem here with weird settings app...(A320FL)
Click to expand...
Click to collapse
in trying to go back to nougat, do you also have the t roaming thing?

YoMarshMellow said:
in trying to go back to nougat, do you also have the t roaming thing?
Click to expand...
Click to collapse
Yes..

I found a fix, reflash the Oreo image but make use of each file in the compressed zip. So the bl file goes to the bl section, ap file goes into ap, cp into cp, csc into csc...
U will lose all ur data though so be careful
I feel like a retard not knowing this lol

YoMarshMellow said:
I found a fix, reflash the Oreo image but make use of each file in the compressed zip. So the bl file goes to the bl section, ap file goes into ap, csc into csc etc...
U will lose all ur data though so be careful
I feel like a retard not knowing this lol
Click to expand...
Click to collapse
So the CSC is the problem 'cause when I flashed Oreo, I used AP, BL and CP but no CSC...

Pagan_Serpent said:
So the CSC is the problem 'cause when I flashed Oreo, I used AP, BL and CP but no CSC...
Click to expand...
Click to collapse
Yes, my problem is a bit different as i only flashed ap so i had no service functionality but after i had reflashed, the phone erased itself and i was back on oreo with the proper settings app and with the ability to make calls and send text messages.
I think it would help to use odin 3.13/3.13.1.

YoMarshMellow said:
this may be the dumbest thing i have ever done. and i feel stupid.
so i saw that 8.0.0 was released for the A5 BTU.
i assume mine was BTU because it was unbranded and I bought my phone from Carphone.
i install the firmware, only to know that i have no service. and in settings it shows up a wierd carrier that i cannot access.
so i plug it into smart switch on my pc, and it shows up as XER instead of BTU.
im so confused, can someone please help me? i feel really dumb
(i have left a screenshot of wierd carrier)
my imei and baseband also show up as unknown
Click to expand...
Click to collapse
Hey, flash modem.bin file from old stock rom and you are good to go ! Had this issue with my S4 .

Switching from ATT to TMobile, questions inside

Hello, I'm currently using a Galaxy s9+ on ATT and plan on switching to Tmobile this week. Besides unlocking the phone do I have to do anything else for the phone to take advantage of TMobile? Do I have to flash TMobile firmware or anything like that in order for the phone to work properly and if so how, I've been out of the flashing game for a LONG time .

No you don't have to flash t mobile rom as I know when you put a new sim the phone reboots and sets the phone up for that carrier that's what it does on my s9 but mine the unlocked one so I got wifi calling with t mobile sim card in my phone

T mobile
The screen shots should show up

same boat but need to flash TMB image
okay hear's the deal, i am in the same boat moved to T-Mobile few days back and i have a Vzw branded S9+. i was of the opinion that things would workout great, but my area has poor t-Mobile network and i have been unsuccessfully attempted to flash TMB firmware on this phone. I have tried just about all combinations, and every-time the flash is done it boots back as a brand new Vzw phone and looks for a Vzw sim. I insert the TMB SIM and things work but not WIFI calling. Any leads?

riyengarxda said:
okay hear's the deal, i am in the same boat moved to T-Mobile few days back and i have a Vzw branded S9+. i was of the opinion that things would workout great, but my area has poor t-Mobile network and i have been unsuccessfully attempted to flash TMB firmware on this phone. I have tried just about all combinations, and every-time the flash is done it boots back as a brand new Vzw phone and looks for a Vzw sim. I insert the TMB SIM and things work but not WIFI calling. Any leads?
Click to expand...
Click to collapse
What odin you use??

1.13.1 patched.
---------- Post added at 02:54 AM ---------- Previous post was at 02:51 AM ----------
Some more details if that helps..
Paid $24 to Sammobil, went through the flashing process and nothing changed. Did this almost 5 times but seems VZW keeps haunting me. Am I doing something wrong? I downloaded the latest firmware RB8 from Aug 2018 for TMB via sammobile flashed the 4 files AP, BT,CP and CSC. Everything went perfect but when it boots back Damn the same old VZW and the OS says u have a non vzw sim. I even flashed the userdata with the other four and separately but no luck. Do we have any success stories and how we dis this correctly? Using Odin 1.13.3 patched version. Tried to downgrade but that failed.

Use 3.13 I believe

Rally517 said:
Use 3.13 I believe
Click to expand...
Click to collapse
Yes sorry typo error, 3.13.1_3B

Not trying to start a new thread with something similar so I'm just gonna post underneath this one. I have an AT&T S9 that is sim unlocked and all but, for the life of me I can't get it to work on Verizon. I've tried changing the bands in the *#*#3696#*#* menu and all I get is, is data. I tried flashing ARG7 unlocked I believe and it still booted with all the AT&T stuff loaded. The build number now shows ARG7 instead of ARG8. I don't know if there's a specific odin / firmware I need to flash in order to be able to get it right. I've been hunting for hours and flashing and I'm at a loss. Thank you guys in advance.

riyengarxda said:
okay hear's the deal, i am in the same boat moved to T-Mobile few days back and i have a Vzw branded S9+. i was of the opinion that things would workout great, but my area has poor t-Mobile network and i have been unsuccessfully attempted to flash TMB firmware on this phone. I have tried just about all combinations, and every-time the flash is done it boots back as a brand new Vzw phone and looks for a Vzw sim. I insert the TMB SIM and things work but not WIFI calling. Any leads?
Click to expand...
Click to collapse
All the carrier stuff is located in the CSC from the flash.
Side note: from what I've read, Verizon locks down the bands and whatnots that stop TMobile stuff from functioning, like WiFi calling.
I've seen people get it working but not the video calls.

thegreatkazoo said:
All the carrier stuff is located in the CSC from the flash.
Side note: from what I've read, Verizon locks down the bands and whatnots that stop TMobile stuff from functioning, like WiFi calling.
I've seen people get it working but not the video calls.
Click to expand...
Click to collapse
Thanks, I really don't care about video calls but WIFI calling is a real need.. any leads?

thegreatkazoo said:
All the carrier stuff is located in the CSC from the flash.
Side note: from what I've read, Verizon locks down the bands and whatnots that stop TMobile stuff from functioning, like WiFi calling.
I've seen people get it working but not the video calls.
Click to expand...
Click to collapse
All my functions work. Video calling etc etc. Unlocked s9. First I az on Boost mobile. Switched to metro. Flashed tmb everything works.

riyengarxda said:
Thanks, I really don't care about video calls but WIFI calling is a real need.. any leads?
Click to expand...
Click to collapse
There a thread around here that talks about how to get the TMobile services but WiFi calling is all they could get to work. You have to flash the CSC (home partition) from TMobile is what I've heard. I've also heard, you can put in a TMobile Sim and it'll just work. But, I think that might be limited to "factory unlocked" phones.

thegreatkazoo said:
There a thread around here that talks about how to get the TMobile services but WiFi calling is all they could get to work. You have to flash the CSC (home partition) from TMobile is what I've heard. I've also heard, you can put in a TMobile Sim and it'll just work. But, I think that might be limited to "factory unlocked" phones.
Click to expand...
Click to collapse
Do you have the thread link? I tried just about as many I could read up..

riyengarxda said:
Do you have the thread link? I tried just about as many I could read up..
Click to expand...
Click to collapse
I'm at work but I'll be off in a bit and I'll hunt it down once I get home.
If I'm not mistaking, it's the one that talks about flashing the u fw to the u1.

riyengarxda said:
Do you have the thread link? I tried just about as many I could read up..
Click to expand...
Click to collapse
https://forum.xda-developers.com/ga...n8-s8x-s9x-oreo-usa-t-mobile-efs-csc-t3772385
Here you go. There's a version 3 on OP web site. Look up my posts there.

Docmjldds said:
https://forum.xda-developers.com/ga...n8-s8x-s9x-oreo-usa-t-mobile-efs-csc-t3772385
Here you go. There's a version 3 on OP web site. Look up my posts there.
Click to expand...
Click to collapse
Read through all the 16 page thread and found very useful comments from you on usage of V3 detonator and Csc changer. I stand confused over just 2 questions;
1. Do I have to root my s9+ which is from vzw
2. It talks about F and FD variant while I have a u variant running snapdragon.
Show me some light .:angel:

riyengarxda said:
Read through all the 16 page thread and found very useful comments from you on usage of V3 detonator and Csc changer. I stand confused over just 2 questions;
1. Do I have to root my s9+ which is from vzw
2. It talks about F and FD variant while I have a u variant running snapdragon.
Show me some light .:angel:
Click to expand...
Click to collapse
I'm on Exynos S9 and rooted. Doubt this will work on a Snapdragon device. Sorry

Docmjldds said:
I'm on Exynos S9 and rooted. Doubt this will work on a Snapdragon device. Sorry
Click to expand...
Click to collapse
Yup exactly my taught... thank you for all the insights..

Last Resort Regarding Carrier Switching

I'd like to start off by apologizing if there's a thread that has answered this. I've spent nearly a week trying to find my answer because, I'm one of those that doesn't like duplicate post to begin with or those who don't google however, I can't find my definite answer and I just want to reassure before going and spending money.
Scenario: I recently have been given an AT&T Galaxy S9 and I'm mad in love with it (using an iPhone X at the moment lol) and I need it to work on Verizon. Of course my first step will be unlocking the device to be able to be used on different networks and I do by putting in the code that I received and it does unlock it. I proceed to put my sim card in it and I notice I can't seem to get service to work. I noticed giving my Note 8 Verizon to my friend who has AT&T, he could put his sim card in and it'll restart with all AT&T functions including the boot logo and all. My S9 AT&T rejects it still. I did try and tinker with the dial codes (*#*#4636#*#*) and setting my bands to LTE/CDMA. Doing this allowed me to receive 4G LTE on the device but, no cellular service. With that being said, I've read on threads that firmwares from certain manufacturers disable bands so I assume AT&T has those disabled that work for Verizon. My next step was trying to get a verizon firmware to work on it. I downloaded the ARG8 U firmware from verizon for it and it still boots AT&T firmware regardless. My last thought would be waiting for the updated V3 U1 Firmware for the S9 and maybe that'll fix it? I just need some opinions on this matter because, if I can't get this to work then I'm going to proceed on buying a new one unlocked.
Thank you guys in advanced and again, if there's already answers for this then I apologize. I've worked with android since the HTC Hero days and I still get stumped on some things haha.

megaghostgamer said:
Thank you guys in advanced and again, if there's already answers for this then I apologize. I've worked with android since the HTC Hero days and I still get stumped on some things haha.
Click to expand...
Click to collapse
Yes.. wait till XAA-U1 is available or an ATT firmware with userdata file inside which has all ATT related files.

nimms said:
Yes.. wait till XAA-U1 is available or an ATT firmware with userdata file inside which has all ATT related files.
Click to expand...
Click to collapse
When you say ATT firmware do you mean Verizon? I'm trying to convert from ATT to Verizon which I've tried a firmware with Verizon's userdata inside and all it did was double my bloatware lol. Had ATT and Verizon BS. As far as the XAA-U1, I understand then.

megaghostgamer said:
When you say ATT firmware do you mean Verizon? I'm trying to convert from ATT to Verizon which I've tried a firmware with Verizon's userdata inside and all it did was double my bloatware lol. Had ATT and Verizon BS. As far as the XAA-U1, I understand then.
Click to expand...
Click to collapse
Yeah, I misread..
try VZW version
https://updato.com/firmware-archive-select-model?record=12EDD7F878D311E89F15FA163EE8F90B
Or VZW U1
https://updato.com/firmware-archive-select-model?record=E2DA06D078D411E89F15FA163EE8F90B
For proper functionality, make sure there's a "userdata" file when you unzip.
Also, use CSC file which wipes the phone, not home csc file which keeps data intact.
If things don't work.. keep sim inside and do a factory reset with sim. it'll ensure proper CSC selection.

nimms said:
Yeah, I misread..
try VZW version
https://updato.com/firmware-archive-select-model?record=12EDD7F878D311E89F15FA163EE8F90B
Or VZW U1
https://updato.com/firmware-archive-select-model?record=E2DA06D078D411E89F15FA163EE8F90B
For proper functionality, make sure there's a "userdata" file when you unzip.
Also, use CSC file which wipes the phone, not home csc file which keeps data intact.
If things don't work.. keep sim inside and do a factory reset with sim. it'll ensure proper CSC selection.
Click to expand...
Click to collapse
See the issue is those links you posted are meant for the V2 bootloader. G960UOYN(2)ARF4 . I've actually tried the U1 and all from V2 but, it gives back that binary fail due to me being on the V3 bootloader. I'll try with the V3 bootloader files for verizon again and do the whole factor reset afterwards. Unfortunately there hasn't been a V3 U1 yet for the S9. Thank you for helping me figure this out, i'll post my results shortly.

nimms said:
Yeah, I misread..
try VZW version
https://updato.com/firmware-archive-select-model?record=12EDD7F878D311E89F15FA163EE8F90B
Or VZW U1
https://updato.com/firmware-archive-select-model?record=E2DA06D078D411E89F15FA163EE8F90B
For proper functionality, make sure there's a "userdata" file when you unzip.
Also, use CSC file which wipes the phone, not home csc file which keeps data intact.
If things don't work.. keep sim inside and do a factory reset with sim. it'll ensure proper CSC selection.
Click to expand...
Click to collapse
Updating from earlier, I tried with the Verizon U3ARG8 file and all it did was add on the bloatware from verizon. I've tried factory resetting and all and it still doesn't want to swap over. Every time it boots, it begins with the AT&T boot logo and proceeds to not give me proper service. I can mess with the LTE bands and get data working, just not service itself.

megaghostgamer said:
Updating from earlier, I tried with the Verizon U3ARG8 file and all it did was add on the bloatware from verizon. I've tried factory resetting and all and it still doesn't want to swap over. Every time it boots, it begins with the AT&T boot logo and proceeds to not give me proper service. I can mess with the LTE bands and get data working, just not service itself.
Click to expand...
Click to collapse
In S8, there's a method using Combination rom (factory binary) to do a proper carrier switch. Take a look and try. Not sure if that would work, but that's an option.

nimms said:
In S8, there's a method using Combination rom (factory binary) to do a proper carrier switch. Take a look and try. Not sure if that would work, but that's an option.
Click to expand...
Click to collapse
Just tried it, once you get in the factory binary, you're supposed to type *#243203855# in the dialer and be able to switch it there however, it's not allowing me to do so. All it does is clear what I've typed.

megaghostgamer said:
Just tried it, once you get in the factory binary, you're supposed to type *#243203855# in the dialer and be able to switch it there however, it's not allowing me to do so. All it does is clear what I've typed.
Click to expand...
Click to collapse
S8 needs flashing canadian CSC before flashing factory binary. Did you try that too?

nimms said:
S8 needs flashing canadian CSC before flashing factory binary. Did you try that too?
Click to expand...
Click to collapse
The Canadian csc is XAC right? Just trying to hunt for one. I don’t see any for the G960U. I see XAS (unknown) but, I don’t believe it’s the same thing.

megaghostgamer said:
The Canadian csc is XAC right? Just trying to hunt for one. I don’t see any for the G960U. I see XAS (unknown) but, I don’t believe it’s the same thing.
Click to expand...
Click to collapse
You must look for G960W files for Canadian csc

nimms said:
You must look for G960W files for Canadian csc
Click to expand...
Click to collapse
Got it, however, since it's the Canada one, it only allows me to change the CSC to companies from Canada. It doesn't allow me to type the code in factory binary but, it does in stock rom with the XAC CSC flashed. I tried the adb shell where you use the echo function but, I get the common problem others do "/system/bin/sh: can't create /efs/imei/mps_code.dat: Permission denied".
Seems though we are getting closer and closer, never seen something so stubborn haha. Sucks there isn't a U3 XAA yet.

megaghostgamer said:
Got it, however, since it's the Canada one, it only allows me to change the CSC to companies from Canada. It doesn't allow me to type the code in factory binary but, it does in stock rom with the XAC CSC flashed. I tried the adb shell where you use the echo function but, I get the common problem others do "/system/bin/sh: can't create /efs/imei/mps_code.dat: Permission denied".
Seems though we are getting closer and closer, never seen something so stubborn haha. Sucks there isn't a U3 XAA yet.
Click to expand...
Click to collapse
Flashing process
Factory binary,
Do reboot to bootloader via ADB,
Flash Canada "Home CSC" (not plain CSC)
Dial *#243203855# via IME button
Choose XAC, let it restart,
On adb shell, Type in
echo "VZW" > /efs/imei/mps_code.dat
(Make sure to include quotes on VZW)
If that's what you did, i think we are done here (Can't think of any other options)
Source : https://forum.xda-developers.com/galaxy-s8/how-to/snap-guide-flashing-standard-fw-carrier-t3625817

nimms said:
Flashing process
Factory binary,
Do reboot to bootloader via ADB,
Flash Canada "Home CSC" (not plain CSC)
Dial *#243203855# via IME button
Choose XAC, let it restart,
On adb shell, Type in
echo "VZW" > /efs/imei/mps_code.dat
(Make sure to include quotes on VZW)
If that's what you did, i think we are done here (Can't think of any other options)
Source : https://forum.xda-developers.com/galaxy-s8/how-to/snap-guide-flashing-standard-fw-carrier-t3625817
Click to expand...
Click to collapse
Meant to reply back but, after flashing the hell out of the phone, it somehow went into XAA CSC and I factory reset it and afterwards it allowed me to connect to Verizon. Thank you so much!

Hi,
Im also trying to convert a VZM S9 to a Canadian CSC. Do the above steps work? because after i flash the factory bin, boot into it, when i try to flash the home_csc from the canadian fw, it always fails, no matter which odin i try. also that IME code, is it only supposed to work once the canadian home_csc as been flashed? because if i try that code in the IME section of the factory bin, i get nothing!

My korean SM-G960N device doesn't connect to H+ or LTE mobile date?

I live in an International region but was sold a Korean device, and it's stuck on E or 3G only, even if I go into Sim Settings or whatever, and select "LTE only" the cellular signal just dies entirely and I can't make or receive calls. when my friend's phone connects to H+ mine only connects to 3G. is there anyway this could be fixed without flashing firmware?
upon further googling, I found out that there is a secret service menu that lets you select bands, but I was unable to access that menu in this ****ty korean piece of **** device.

the menu should look like the attached image.

Coomer91 said:
I live in an International region but was sold a Korean device, and it's stuck on E or 3G only, even if I go into Sim Settings or whatever, and select "LTE only" the cellular signal just dies entirely and I can't make or receive calls. when my friend's phone connects to H+ mine only connects to 3G. is there anyway this could be fixed without flashing firmware?
upon further googling, I found out that there is a secret service menu that lets you select bands, but I was unable to access that menu in this ****ty korean piece of **** device.
Click to expand...
Click to collapse
the Korean model is actually pretty darn decent. What is your aversion to flashing firmware? if you use the HOME_CSC you dont really notice a change as it doesnt factory reset the device and if its the same version of android (pie, oreo etc etc) it doesnt require the device to do anything really

youdoofus said:
the Korean model is actually pretty darn decent. What is your aversion to flashing firmware? if you use the HOME_CSC you dont really notice a change as it doesnt factory reset the device and if its the same version of android (pie, oreo etc etc) it doesnt require the device to do anything really
Click to expand...
Click to collapse
because I couldn't flash an international CSC no matter what I tried, it fails constantly with PIT errors. that why I was wondering if there was any way to change the cellular bands some other way.

Coomer91 said:
because I couldn't flash an international CSC no matter what I tried, it fails constantly with PIT errors. that why I was wondering if there was any way to change the cellular bands some other way.
Click to expand...
Click to collapse
you dont need to flash the PIT, as a matter of fact, id not recommend flashing it at all if youre not having internal storage issues.

youdoofus said:
you dont need to flash the PIT, as a matter of fact, id not recommend flashing it at all if youre not having internal storage issues.
Click to expand...
Click to collapse
It doesn't matter if I flashed the PIT or not, it will fail regardless with same "secure check fail (PIT)" error. i've given up at this point.

Coomer91 said:
It doesn't matter if I flashed the PIT or not, it will fail regardless with same "secure check fail (PIT)" error. i've given up at this point.
Click to expand...
Click to collapse
secure check fail is usually due to custom firmware attempted to be flashed without unlocking your bootloader.
can you get a log of the Odin error? also there are errors that can show on the phone itself that are useful. If youve given up, i get it, but i dont believe youre stuck

youdoofus said:
secure check fail is usually due to custom firmware attempted to be flashed without unlocking your bootloader.
can you get a log of the Odin error? also there are errors that can show on the phone itself that are useful. If youve given up, i get it, but i dont believe youre stuck
Click to expand...
Click to collapse
So you're telling me that flashing a G960F firmware on a G960N device doesn't require repartitioning? Cuz a few people told me the F CSC and the N CSC have different partitions.

Coomer91 said:
So you're telling me that flashing a G960F firmware on a G960N device doesn't require repartitioning? Cuz a few people told me the F CSC and the N CSC have different partitions.
Click to expand...
Click to collapse
i never recommend re-partitioning unless strictly necessary, and in this case, id say no. Its not needed

youdoofus said:
i never recommend re-partitioning unless strictly necessary, and in this case, id say no. It's not needed
Click to expand...
Click to collapse
so you're sure that there is no difference in the partition between N and F CSCs? cuz the guy who made the SoLdierRblahblah Rom, said that the N CSC partition is smaller than the F one.
https://forum.xda-developers.com/showpost.php?p=80765449&postcount=4897

Coomer91 said:
so you're sure that there is no difference in the partition between N and F CSCs? cuz the guy who made the SoLdierRblahblah Rom, said that the N CSC partition is smaller than the F one.
https://forum.xda-developers.com/showpost.php?p=80765449&postcount=4897
Click to expand...
Click to collapse
im not saying that there isnt a difference between the partitions, but i AM saying that its irrelevant to your issue. What the dev is saying in your linked post is that the CSC that was flashed was too big for the partition it was headed for, which is odd.
Id youre dead set on flashing the N PIT, get the patched version of Odin and you should be able to flash whatever you want as it is patched to ignore errors and just do what its told without a safety net

Coomer91 said:
So you're telling me that flashing a G960F firmware on a G960N device doesn't require repartitioning? Cuz a few people told me the F CSC and the N CSC have different partitions.
Click to expand...
Click to collapse
Sorry to bump an ancient post but I have to ask, did you do it? Is it safe to flash G960F firmware on a G960N device? Will it transform the G960N into a G960F? Did you try using a patched Odin like @Youdoofus suggested? My issue is much smaller, I can't get VoLTE in LTE only mode while it works fine in autoconnecct mode. While the phone randomly switching between E/H+/LTE (crappy reception in my area) is annoying, it's definitely not worth bricking my device so please help.
Also @Youdoofus I downloaded just the CP and BL files for G960F and tried to flash them on my G960N but failed with Secure Check Failed (Bootloader) or Secure Check Failed (Radio) depending on what I flash. Will it work if I do it using the patched Odin or will it brick my phone? Finally, In download mode Secure Download is set to enabled is that bad?
I know I ask too many (stupid?)questions(it's a curse), so please bear with me and thanks in advance!

Tried to flash G988W firmware onto my G988U1 phone. SIM card not recognized

I live in Canada. I purchased an S20 Ultra off a seller on Canadian best buy (open box). I assumed it'd be a Canadian variant, but it was an unlocked US version (U1 firmware). OK whatever, but it meant my Samsung Pay doesn't work, along with a few other calling features.
I downloaded the patched Odin, downloaded the G988W firmware (with XAC CSC) with Frija, added the appropriate files to Odin (used Home CSC), and flashed it. The flashing itself went fine, but when I went to re-insert my SIM...nothing. It didn't even error out and say "No SIM Detected", I just had no coverage, and in SIM manager, both slots were empty.
Freaked out, and eventually flashed back to G988U1/XAA and thank Christ it works now. But my question is...why?
I dug though this forum before doing it to try and anticipate any issues. Followed the instructions to the letter, nowhere said this would be an issue. Couldn't even find any relevant support questions for this issue on this model. Not sure if it's a new development, but I absolutely don't want to risk messing my phone up further if I reattempt.
Bonus question: My CSC info is: XAA/XAA,XAA/SPR. Does that mean that it was originally a Sprint model phone, someone's flashed the firmware to an unbranded version, then sold it off as New (Open Box)?

You can't just flash a firmware from a different phone. The hardware is different, so the way to communicate with it is different. You're lucky it even booted, I wouldn't have expected that even. You're simply stuck with the original firmware and CSC list. Or, maybe you could try with custom ROMS but I wouldn't be so sure about it. Either way, you'll have to use a ROM/firmware that is built for your phone (G988U1).

Mwyann said:
You can't just flash a firmware from a different phone. The hardware is different, so the way to communicate with it is different. You're lucky it even booted, I wouldn't have expected that even. You're simply stuck with the original firmware and CSC list. Or, maybe you could try with custom ROMS but I wouldn't be so sure about it. Either way, you'll have to use a ROM/firmware that is built for your phone (G988U1).
Click to expand...
Click to collapse
Huh I thought the actual hardware between U1 and W was the same? They're both Snapdragons. Besides I've seen other posts of people doing the same (tbh, they were going from W to U1, but still)

Mwyann said:
You can't just flash a firmware from a different phone.
Click to expand...
Click to collapse
Oh but you CAN.
U, U1, and W have all been cross-flashable ever since Samsung first introduced universal hardware, starting with the S8

Jetrel1 said:
Bonus question: My CSC info is: XAA/XAA,XAA/SPR. Does that mean that it was originally a Sprint model phone, someone's flashed the firmware to an unbranded version, then sold it off as New (Open Box)?
Click to expand...
Click to collapse
Probably. Very common for online sellers to do.
The key probably lies in what the CSC shows as after flashing W firmware. If it stays as XAA, changing the CSC manually to a Canadian one could possibly make it work

iBowToAndroid said:
Oh but you CAN.
U, U1, and W have all been cross-flashable ever since Samsung first introduced universal hardware, starting with the S8
Click to expand...
Click to collapse
I thought so too, lol
Any thoughts on why my flash caused the SIM issue? Did I maybe just install the wrong version? I don't think I did, I used Frija
Some further research led me to the subject of accidentally mucking up the modem firmware which I might have done

Jetrel1 said:
I thought so too, lol
Any thoughts on why my flash caused the SIM issue? Did I maybe just install the wrong version? I don't think I did, I used Frija
Some further research led me to the subject of accidentally mucking up the modem firmware which I might have done
Click to expand...
Click to collapse
See my other post above

iBowToAndroid said:
See my other post above
Click to expand...
Click to collapse
My bad I didn't even compute. Thanks!

Jetrel1 said:
I live in Canada. I purchased an S20 Ultra off a seller on Canadian best buy (open box). I assumed it'd be a Canadian variant, but it was an unlocked US version (U1 firmware). OK whatever, but it meant my Samsung Pay doesn't work, along with a few other calling features.
I downloaded the patched Odin, downloaded the G988W firmware (with XAC CSC) with Frija, added the appropriate files to Odin (used Home CSC), and flashed it. The flashing itself went fine, but when I went to re-insert my SIM...nothing. It didn't even error out and say "No SIM Detected", I just had no coverage, and in SIM manager, both slots were empty.
Freaked out, and eventually flashed back to G988U1/XAA and thank Christ it works now. But my question is...why?
I dug though this forum before doing it to try and anticipate any issues. Followed the instructions to the letter, nowhere said this would be an issue. Couldn't even find any relevant support questions for this issue on this model. Not sure if it's a new development, but I absolutely don't want to risk messing my phone up further if I reattempt.
Bonus question: My CSC info is: XAA/XAA,XAA/SPR. Does that mean that it was originally a Sprint model phone, someone's flashed the firmware to an unbranded version, then sold it off as New (Open Box)?
Click to expand...
Click to collapse
I Just did exactly the same and got a tmobile variant but want the W preferably the samsung factory rom not a carrier one. Which guide did you follow? I found this for the 21 Ultra and expect the steps to be similar https://forum.xda-developers.com/t/...-samsung-unlocked-bloatfree-firmware.4224423/

What calling features don't work in Canada? I have a W variant, live in Canada, and want an U1 to get esim working. I am also looking for a guide to follow to flash my phone.

funrunner said:
What calling features don't work in Canada? I have a W variant, live in Canada, and want an U1 to get esim working. I am also looking for a guide to follow to flash my phone.
Click to expand...
Click to collapse
Samsung Pay doesn't work - that's a big one for me, it's a pain in the **** losing that. Will only accept US ZIP codes when setting up.
Caller ID doesn't work
That extra info you get when texting (like seen/read stuff) doesn't work in the native Samsung text app, you have to use google messages (yeah, no)
I'm sure there's other stuff but those are the main ones