Can I flash a firmware with a different CSC code? - General Questions and Answers

I recently bought an unlocked AT&T Samsung S20 ULTRA 5G (SM-G988U), it doesn't get any OTA updates, I found out that I would need an AT&T sim card to do so but I'm not an US resident, so I can't get one.
Since AT&T doesn't publicly publish their firmware files and I want to update my phone, I was wondering if flashing my phone using another firmware with a different CSC code like USC (US cellular), would be risky or is it a safe procedure?
This would be my first time doing this procedure and that's the only part that really got me thinking.
Thanks!

U firmware is identical, no matter which carrier it's from. So if AT&T's latest release ends in UH2 and there is also a UH2 firmware from US Cellular, flashing it would be just like flashing the AT&T firmware, if it were available

Also have same question I have Samsung S20 . SM-G988U , service provider software version SAOMC_SM-G988U_OYN_ATT_RR_0018ATT/ATT/ATT Baseband Version G988USQS2SUE2, I am not able to get new updates as I am not in US, I need suggestion which firmware of android 12 I should update on my phone.

Related

Upgrade Software

My Samsung Galaxy S7 has the Vodaphone Baseband version G930FXXU1DQIL Its offering
to upgrade my firmware to a new version G930FXXU2DRB6
Is there anything stopping me putting a non carrier related Software on the
handset. I was considering installing a BTU version , PDA G930FXXS1DQLC. What is the difference from one version to
another? Is there much likelyhood in bricking the handset by changing the Firmware
So long as you use G930F firmware, you can flash any version and it should be fine. Just make sure you flash all 4 files.
Carrier specific firmware is what lets carrier features like VoLTE to work, but you can flash the BTU version, then flash just your carriers CSC and carrier features will work.

General G996U and G996U1 Firmware Links and Flashing Discussion Here

For those who aren't already aware, G996U is the model number of all of the US carrier versions of the S21+. The G996U1 is the model number of the same device, but sold by Samsung SIM unlocked and with no carrier bloatware. Firmware is 100% interchangeable among these models: any U or U1 firmware version can be flashed to any U or U1 device at any time, assuming that you're not trying to downgrade the bootloader. A "U to U" or "U1 to U1" flash does not require a factory reset, but changing from one firmware to the other will require one. Also, U firmware is identical for the 4 base files (AP, BL, CP, CSC) for each individual build, no matter which carrier it comes from. So if you download 2 different carrier versions of the exact same build, the 4 base files will be identical. Where the firmware differs is in the USERDATA file - that's where the carrier bloatware and customizations reside.
Manual Odin flashing is designed for those who:
- want to manually update to a newer version of U firmware on their U device, either because they don't want to wait for their carrier's OTA or because OTAs aren't working on their device, or a different carrier got a new feature/patch before they did
- want to flash U1 firmware to their U device
- want to convert from U1 firmware to carrier U firmware
- want to convert from one carrier's U firmware (with all apps and bloatware) to a different carrier's U firmware (with all apps and bloatware)
For those who aren't already aware, anyone can now download firmware for almost any Samsung device any time that they want, via the various firmware download tools posted here on XDA like SamFirm or Frija. There are threads and info about them here on XDA so I won't waste time explaining - do a search if you're not already familiar with these tools. But they only provide whatever the latest/newest/current version is - nothing older. I pay for a subscription to a site that gets the official releases (usually) before they hit the firmware download tools, so that's where my files come from.
This is not a "beginner's guide to Odin flashing" -type post/thread, so I won't list basic, step-by-step flashing instructions. My threads are geared towards those who already know what they're doing. If you're new to manually flashing Samsung firmware (or haven't done it in a long time), I recommend you consult one of those "beginner's" guides- there are tons of them here on XDA.
Happy flashing!
U firmware: https://www.androidfilehost.com/?w=files&flid=322091
U1 firmware: https://www.androidfilehost.com/?w=files&flid=322092
Notes:
- DON'T QUOTE THE OP WHEN YOU REPLY, kthx
- I have lots of threads just like this one for other Samsung flagships, if it interests you. For those who have already made use of my previous threads for a different device and are upgrading to an S21, welcome back
- My zips are compressed extra small for space and bandwidth savings. The default Windows extractor can't handle it, so you'll need a 3rd party tool like 7zip, WinRAR, etc
- it's quite time consuming to download the files, zip them up, and upload them to AFH. And, I do threads like this for every single Sx and Note x model, so I won't be uploading every single version. The only full builds that I upload are ones where I get access to a new bootloader and/or Android version early, before they hit the firmware download tools.
- My naming method for folders on AFH is: build - bootloader - Android version
So "SAT - 1 - 9.0" means the full build number ends in SAT, it's bootloader version 1, and it's Android 9.0. When bootloader and Android versions increment, the first build to have those changes will have its folder notated appropriately.
- HOME CSC file keeps data intact; using the other CSC will wipe data. Flashing USERDATA will also wipe data.
- Since AT&T doesn't allow their firmware to be publicly available (for any of their devices), I'll try to always upload at least one USERDATA per bootloader increment for AT&T (and Cricket, if they get this model). I'll also upload any full builds if AT&T is the only carrier to get that specific build, because you won't be able to find the files anywhere else.
- For identifying USERDATAS, and to know what region/CSC to use in the firmware download tools if you're downloading yourself:
AIO = Cricket (not available via firmware download tools)
ATT = AT&T (not available via firmware download tools)
BST = Boost Mobile
CCT = Xfinity Mobile (Comcast)
CHA = Spectrum Mobile (Charter)
DSH = Dish Network
SPR = Sprint
TMB = T-Mobile
TMK = Metro PCS
USC = US Cellular
VZW = Verizon (available via firmware download tools, but Manual Entry is required - Auto will not work)
XAA = U1 firmware
- the correct procedure for switching from one carrier's firmware to another is:
1. Flash full U1 firmware package including non HOME CSC
2. Upon boot, insert a SIM of the carrier whose firmware you want
3. Watch for the popup that says "reboot to apply new carrier settings" etc, and do it
4. After that restart completes, reboot back to Download mode and flash the full U firmware package, with the USERDATA file of the carrier whose firmware you want
Initial U firmware and AT&T USERDATA are posted, along with U1 firmware. U firmware is not yet accessible in the firmware download tools like SamFirm and Frija, but if anyone wants a different carrier's USERDATA (for flashing bloatware to a U1 device or for converting a U device from one carrier's bloatware to a different one), let me know and I'll get it for you
Are the firmware in OP compatible for the S21 (Non-plus)?
craznazn said:
Are the firmware in OP compatible for the S21 (Non-plus)?
Click to expand...
Click to collapse
This thread is in the S21+ forum, not the S21 forum.
This thread is for model numbers G996U and G996U1, not G991U or G991U1.
If you're looking for S21 firmware, that will be found in the S21 forum
I agree with you
Does the firmware control the SIM lock? So, can you flash the U1-XAA firmware and use say a phone purchased from AT&T on another carrier? Or do you need to do the SIM unlock before flashing?
3BeersKen said:
Does the firmware control the SIM lock? So, can you flash the U1-XAA firmware and use say a phone purchased from AT&T on another carrier? Or do you need to do the SIM unlock before flashing?
Click to expand...
Click to collapse
SIM unlock always goes much deeper than firmware. Flashing U1 will never automatically unlock any model - the unlock has to be done separately. If desired, I can provide a recommendation for a professional 3rd party business to do the unlocking, for any interested users who may not meet the carrier's unlock requirement(s).
Thanks. That's what I figured, but wanted to make sure. I like to get off of the AT&T firmware as quickly as possible as you can't get their updates unless you have an active SIM in the phone.
3BeersKen said:
You can't get their updates unless you have an active SIM in the phone.
Click to expand...
Click to collapse
Correct. They're A-holes like that haha
iBowToAndroid said:
Correct. They're A-holes like that haha
Click to expand...
Click to collapse
I got TMobile s21+ and want flash to u1,do you know which odin should I use, thanks
yijinsa said:
I got TMobile s21+ and want flash to u1,do you know which odin should I use, thanks
Click to expand...
Click to collapse
3.14.1 patched
I don't have my S21+ yet but it will be here soon. I ordered from Samsung and selected the Verizon version as unlocked was considerably more expensive.
Does anyone know what Verizon specific bloatware the S21+ has?
Are there certain apps which can be uninstalled with the U1 version but not the Verizon U version?
Are there any potential speed benefits on the 5G network that would be lost using the U1 version, or features like tethering that won't work?
For updates in the future, would they arrive faster on the U1 version, slower, or the same?
My main purpose in flashing from U to U1 is to free up the maximum amount of space of the 128 GB while still retaining 100% of the speed and features I would have with the Verizon version.
Thank you for educating me! It's been a couple years since I flashed my Note 8.
I order a unlocked S21+ U1 version straight from Samsung and didn't have to put in any VZW info.
There is a buttload of Samsung bloatware but no VZW except fot MyVZX
Have anyone here with T-mobile version stuck on TMB/TMB/TMB after going to U1 firmware?
Someone over S21 Ultra have this problem, but I'm not sure if Android 11 tinker or T-mobile side. Used to be XAA/XAA/TMB
x1tymez said:
Have anyone here with T-mobile version stuck on TMB/TMB/TMB after going to U1 firmware?
Someone over S21 Ultra have this problem, but I'm not sure if Android 11 tinker or T-mobile side. Used to be XAA/XAA/TMB
Click to expand...
Click to collapse
Yes, that seems to be a common issue with T-Mobile S21s - all 3 models
iBowToAndroid said:
Yes, that seems to be a common issue with T-Mobile S21s - all 3 models
Click to expand...
Click to collapse
You think there will be a fix for this? It's weird that dialer codes also don't work.
x1tymez said:
Have anyone here with T-mobile version stuck on TMB/TMB/TMB after going to U1 firmware?
Someone over S21 Ultra have this problem, but I'm not sure if Android 11 tinker or T-mobile side. Used to be XAA/XAA/TMB
Click to expand...
Click to collapse
I've got a T-Mobile locked that I was able to get flashed over to U1 without much trouble. Shows mode number SM-G996U1 now, build number shows same.
edit: Nevermind, I see the TMB/TMB/TMB
krisology said:
You think there will be a fix for this? It's weird that dialer codes also don't work.
Click to expand...
Click to collapse
Dialer codes don't work? On which firmware?
iBowToAndroid said:
Dialer codes don't work? On which firmware?
Click to expand...
Click to collapse
XAA U1, VZW U1, stock TMB U, and I've tried the TLI U1 above and couldn't get it to work. Using google dialer, I input the codes like *#*#27262826#*#* and as soon as I type the last star it just disappears and nothing pops up. I tried with T-Mobile and Verizon sim.
krisology said:
XAA U1, VZW U1, stock TMB U, and I've tried the TLI U1 above and couldn't get it to work. Using google dialer, I input the codes like *#*#27262826#*#* and as soon as I type the last star it just disappears and nothing pops up. I tried with T-Mobile and Verizon sim.
Click to expand...
Click to collapse
Dialer codes usually don't work on VZW firmware, whether U or U1. But they almost always work on TMB and all others.
Have you tried *#06# ?

ATT Velvet doesn't receive OTAs

Hello, I have bought an LG Velvet ATT unlocked. I cannot update via OTA because I think it needs an ATT account and sim card for it to update via the ATT network but I live in Europe. Can I manually install the OTAs relesed by ATT (although I can't find any ATT ones) or do I have to flash another stock firmware that releses updates without a sim? Would it be possible to flash the Canadian android 11 stock firmware since it has the same model number than ATT LM-G900UM? Obviously the software version numbers are slightly different. I want to keep LGs software because I need it for the pen support.
Thanks in advance

Question I have an unlocked AT&T Galaxy S21+ outside of the US. If I flash a different firmware(USA - USC) with a different CSC, will I be able to receive OTA

Hello, I would like to preface this by saying that I don't actually live in the US. I got this used unlocked AT&T Galaxy S21+ a few months back and an issue I noticed after using it for a while was the fact I was not receiving any OTA updates due to the fact I was not using an AT&T SIM card.
Now I want to switch AT&T to carrier-free firmware where I will be able to get regular OTA updates automatically
My current specs:
Model: SM-G996U
chip: Snapdragon 888
Baseband version : G996USQU1ATLF
CSC : G996UOYN1ATLF
AP/CP : G996USQU1ATLF
Is it suitable for installation?
https://www.sammobile.com/samsung/g.../SM-G996U/USC/download/G996USQU5CVDB/1640229/
N.B/: May doing this flash will brick or damage my phone?
On SamMobile, underneath my device model, there list of several firmware labeled with different US carriers. As long as the firmware I flash is under the model number I have (SM-G996U), nothing should break, right?
Please suggest me firmware. I want to get rid of carrier barrier and want to get regular updates automatically safely.
Did you try the rom? I have the same problem
OTA is CSC based. You'd have to use Samkey to unlock the CSC to a unlocked US one.
Flash the u1 xaa firmware. Works on my phone in canada
I have a similar issue!
So I received a refurbished S21+, it is unlocked and all but it has AT&T bloatware and I can't update to oneui 5.0... I live in italy but this phone comes from Germany and apparently has a US AT&T firmware (SM-G996U-OYN-ATT). I was following a tutorial with odin to flash to SM-G996B with ITV, which is the italian version with android 12 and oneui 4.1.1 is it safe to do so and then get the android 13 update the standard way? Could I straight up get android 13 and oneui 5 flashing the most recent rom or is it even worse?
The other solution I thought about is that I could just get the U1 XAA, but i have U for now and I don't quite understand if it's completely risk free or not.
Shohan112 said:
Hello, I would like to preface this by saying that I don't actually live in the US. I got this used unlocked AT&T Galaxy S21+ a few months back and an issue I noticed after using it for a while was the fact I was not receiving any OTA updates due to the fact I was not using an AT&T SIM card.
Now I want to switch AT&T to carrier-free firmware where I will be able to get regular OTA updates automatically
My current specs:
Model: SM-G996U
chip: Snapdragon 888
Baseband version : G996USQU1ATLF
CSC : G996UOYN1ATLF
AP/CP : G996USQU1ATLF
Is it suitable for installation?
https://www.sammobile.com/samsung/g.../SM-G996U/USC/download/G996USQU5CVDB/1640229/
N.B/: May doing this flash will brick or damage my phone?
On SamMobile, underneath my device model, there list of several firmware labeled with different US carriers. As long as the firmware I flash is under the model number I have (SM-G996U), nothing should break, right?
Please suggest me firmware. I want to get rid of carrier barrier and want to get regular updates automatically safely.
Click to expand...
Click to collapse
I'm having the same issue with my Samsung S20 Ultra 5G SM-G988U i bought the device yesterday and it accept my local Sim here but the issue is that there is limited features, for example I can't turn On/off my mobile data on and I can't change network mode like selecting from 4G to 5G

Question AT&T Galaxy s22 Ultra sm-908u..can anything at all be done with an AT&T variant

There are so many threads I can't weed out what's possible..
I know rooting isn't possible... My oem switch is disabled and no tricks worked.
Can I load a different firmware? I see there is a guide for sm-908u but doesent specify the att variant
All the U firmware is the same. It will provision to your Sim. At&t sometimes has a different build number from the other carriers. If that is the case then you need to stay with At&t build number to get OTA updates. But if the Ota falls in line with other carriers you can flash with Odin and be ok to recieve Ota from At&t. But if you flash a different build number, which ok, you will have eventually flash the correct firmware that At&t device is on in order to get Ota
Can I directly flash T-Mobile firmware on a AT&T SM S908U?
At&t never post their firmware..
Yes all the firmware is the same. If you have At&t Sim, the firmware will provision to At&t sim

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