Hello,
I have a SIM unlocked S21 from Xfinity Mobile that I'm now using on Verizon Wireless. I need to change the CSC to VZW, anyone know how? I tried all the dialer codes, and also SamKEY but no luck so far.
SamKEY says "unsupported firmware, please downgrade your firmware".
Since January 2021, it's not easy to change CSC, some people do it by flashing firmwares then block whatever app checks SIM & CSC compatibility.
You can check this thread if you're into action.
Thanks, I tried that but somehow it ignores that the VZW SIM card is VZW, and it keeps the CSC as CCT/CCT/CCT.
Even putting in an AT&T sim card, it still keeps it as CCT/CCT/CCT. The carrier name is stuck as "Xfinity Mobile" also, no matter the SIM.
I wish Samsung would implement the "BYOD" thing already for this phone.. Or maybe SamKEY will work eventually...
What's interesting is that it changes the APN to the correct one automatically for the 3 SIM cards I've tried (VZW, CCT, ATT)
Firmware bug I guess, or Samsung has not yet fully implemented the "BYOD" feature referenced here:
Move your Galaxy phone to a different service carrier
If you unlock your phone to use with another carrier, it's easy to take advantage of all your new carrier's features without losing any of your data.
www.samsung.com
UPDATE: SamKEY worked!!
I was able to change the CSC to the correct carrier!
quadrun1 said:
UPDATE: SamKEY worked!!
I was able to change the CSC to the correct carrier!
Click to expand...
Click to collapse
how many credits do I need to change CSC?
On the samkey page it says that you need 8 credits
No, if I remember correctly it's only 1 credit to change the CSC.
See here:
https://www.reddit.com/r/GalaxyS21/comments/lm0at9
Related
Hi, i have been trying to find an answer to this after hours of searching i've come up short and confused.
I recently switched from tmobile to verizon, and i paid off my tmobile s9+ and had it sim unlocked. When i put my verizon sim in it, nothing really happens. either it tells me that it can't register on the network or to insert a tmobile sim card.
I have tried using reset and factory reset. I have also tried the method of holding the volume bixby and power and doing a factory reset, then putting the sim in, rebooting, etc. That doesn't work either.
I see several people trying to go from verizon to tmobile, but i haven't been able to find anyone going from tmobile to verizon, and what method i need to do to get this to work, if its possible at all. Any help would be so much appreciated!
gigatigga said:
Hi, i have been trying to find an answer to this after hours of searching i've come up short and confused.
I recently switched from tmobile to verizon, and i paid off my tmobile s9+ and had it sim unlocked. When i put my verizon sim in it, nothing really happens. either it tells me that it can't register on the network or to insert a tmobile sim card.
I have tried using reset and factory reset. I have also tried the method of holding the volume bixby and power and doing a factory reset, then putting the sim in, rebooting, etc. That doesn't work either.
I see several people trying to go from verizon to tmobile, but i haven't been able to find anyone going from tmobile to verizon, and what method i need to do to get this to work, if its possible at all. Any help would be so much appreciated!
Click to expand...
Click to collapse
Use Odin to flash U1 and then go back to U. Just leave the SIM in. Don't use HOME CSC.
CrazyApe18 said:
Use Odin to flash U1 and then go back to U. Just leave the SIM in. Don't use HOME CSC.
Click to expand...
Click to collapse
That still may not help, remember Verizon is still CDMA and the T Mobile branded phone does not have CDMA bands activated and they may not even be on the phone, I don't know. Granted band 13 should work fine, being LTE, but could the sim be looking for a CDMA radio and that is why it is not working?
uzupan said:
That still may not help, remember Verizon is still CDMA and the T Mobile branded phone does not have CDMA bands activated and they may not even be on the phone, I don't know. Granted band 13 should work fine, being LTE, but could the sim be looking for a CDMA radio and that is why it is not working?
Click to expand...
Click to collapse
The hardware is identical for all US Galaxy S9 phones. Any bands that may be missing will be resolved by flashing firmware. OP could also just stay with U1 if they want unlocked, and all bands would still be there.
CrazyApe18 said:
The hardware is identical for all US Galaxy S9 phones. Any bands that may be missing will be resolved by flashing firmware. OP could also just stay with U1 if they want unlocked, and all bands would still be there.
Click to expand...
Click to collapse
That is good to know, I sure hope it works for him.
Thank you for the replies, i will try this and post back!
Well sadly with the u1 firmware files, i get an auth error SW REV CHECK FAIL. =/
CrazyApe18 said:
The hardware is identical for all US Galaxy S9 phones. Any bands that may be missing will be resolved by flashing firmware. OP could also just stay with U1 if they want unlocked, and all bands would still be there.
Click to expand...
Click to collapse
As per Samsung chat support, I've asked if the dual sim version (international) will work with Verizon. I've also asked the rep if I can switch carriers with a locked phone. They said that essentially, all phones were manufactured with the CDMA and GSM band compatibility, it just needs to be unlocked and the US versions will work on any carrier in the US and the international version (dual sim) needs to be unlocked and it will work with any carrier in any country.
That said, it seems that you're just having an unlocking issue - which is good and bad. I hope you figure this out. Try using Odin 3.13, get the CORRECT firmware for U1 or U(VZW) to flash your phone
eyewin said:
As per Samsung chat support, I've asked if the dual sim version (international) will work with Verizon. I've also asked the rep if I can switch carriers with a locked phone. They said that essentially, all phones were manufactured with the CDMA and GSM band compatibility, it just needs to be unlocked and the US versions will work on any carrier in the US and the international version (dual sim) needs to be unlocked and it will work with any carrier in any country.
That said, it seems that you're just having an unlocking issue - which is good and bad. I hope you figure this out. Try using Odin 3.13, get the CORRECT firmware for U1 or U(VZW) to flash your phone
Click to expand...
Click to collapse
Only one small correction to what they told you: The 965F (international), will not have CDMA capabilities. That might not be a problem on some US carriers. But if you can't get VoLTE working on VZW with 965F, then you're dead in the water, since you don't have 1x CDMA calling to fall back on. It becomes a data-only device. I don't have experience with it, but I wouldn't be surprised if the VoLTE doesn't work on US carriers. For GDM/WCDMA carriers, you'd probably be just fine with 965F. Even if VoLTE doesn't work, you'd still be able to call.
Hope this helps.
eyewin said:
That said, it seems that you're just having an unlocking issue - which is good and bad. I hope you figure this out. Try using Odin 3.13, get the CORRECT firmware for U1 or U(VZW) to flash your phone
Click to expand...
Click to collapse
Thanks for your reply, any idea where to get these? I'm seeing all kinds of universal stuff and people saying carrier specific don't exist, etc etc. If you happen to know i'd be extremely grateful
gigatigga said:
Thanks for your reply, any idea where to get these? I'm seeing all kinds of universal stuff and people saying carrier specific don't exist, etc etc. If you happen to know i'd be extremely grateful
Click to expand...
Click to collapse
Step 1
Can you find out the exact model number?
For T-Mobile, it will be one of these :
SM-G965UZKATMB (Midnight Black)
SM-G965UZBATMB (Coral Blue)
SM-G965UZPATMB (Lilac Purple)
The U is the important part, as a previous poster explained that the F models do not have CDMA support (forget what that actually means, just know its necessary for verizon)
Step 2
Next, make sure that the carrier version is correct.
Example: SM-G965UZKATMB
BST Boost
VZW Verizon
ATT ATT
USC US Cellular
ACG C Spire
TMK MetroPCS
VMU Virgin Mobile
TFN Tracfone
XAS Sprint
TMB T-Mobile
XAA Unlocked US
SPR Sprint
CCT Xfinity Mobile
Essentially, you need the firmware that starts with SM-G965U and ends with VZW
Step 3
I'm not 100% sure on how to flash from carrier to carrier but there will be a list of directions. You may need to do some research there to see if it will void samsung warranty (aka 'trip knox') or anything like that, if that matters to you. I think only a modified version of Odin will be able to do this.
Download Odin v3.13.1
Extract the firmware file you just downloaded. You should get 5 files:
AP (System & Recovery)
BL (Bootloader)
CP (Modem / Radio)
CSC_OXM (OXM CSC file, will wipe your phone)
HOME_CSC_OXM (OXM CSC file, will NOT wipe your phone)
Add each file to it's respective field in Odin v3.13.1. Use CSC_OXM if you want to do a clean flash and HOME_CSC OXM if you want to keep your apps and data.
Reboot your phone in Download / Odin mode with the following button combo: POWER + VOLUME DOWN + BIXBY
Once in download mode, connect your phone to the PC, preferably using the original USB cable you got with your phone. Odin should detect your device and a blue box will show up with the COM port number.
Do NOT tick any extra boxes. The only options to be ticked are F.Reset Time and Auto-Reboot.
Click the start button, wait for Odin to say 'PASS'. Once the flash is complete, your phone will reboot.
Click to expand...
Click to collapse
Step 4
To download firmwares, google "SAMMOBILE website: /firmwares/galaxy-s9-plus/SM-G965U"
Looks like the latest verizon firmware is here: SAMMOBILE website /firmwares/galaxy-s9-plus/SM-G965U/VZW/download/G965USQS2ARF4/223287
(I'm not yet allowed to post links)
Hey thanks a bunch, I’ll give this a shot when I get home tonight. It very well may be that the rom I got wasn’t the right one. Other threads I’ve read seemed to indicate that everything was universal now and by having the SIM card in the phone while flashing, it would download the carrier specific stuff automatically. That part at least doesn’t appear to be the case since the phone wouldn’t accept it. But I’ll download some of the carrier specifics and see what happens. Thanks again!
Did you get it to work after all?
Sorry that i forgot to update! I did get it working, but it required a bit more discussion and help on a reddit discussion someone started. I noticed that someone asked this exact question and i pointed him to this thread where he was able to get it working, then helped me with which roms he used, and i got it working as well! I've been using it daily for almost a month now. Thanks so much for everyones help, i hope that if anyone else is trying to do this, between the two threads it can help. Heres the link to the reddit thread https://old.reddit.com/r/verizon/comments/909iag/tmobile_s9_on_verizon/
gigatigga said:
Sorry that i forgot to update! I did get it working, but it required a bit more discussion and help on a reddit discussion someone started. I noticed that someone asked this exact question and i pointed him to this thread where he was able to get it working, then helped me with which roms he used, and i got it working as well! I've been using it daily for almost a month now. Thanks so much for everyones help, i hope that if anyone else is trying to do this, between the two threads it can help. Heres the link to the reddit thread https://old.reddit.com/r/verizon/comments/909iag/tmobile_s9_on_verizon/
Click to expand...
Click to collapse
Awesome gigatigga - thanks for getting back. I'm on the verge of trying this. I owe some money on my S9 plus on t-mobile but before i paid it off wanted to make sure all is good.
How are the speeds? Everything working ok? Thanks again! :good::good:
Edit: I was all set to do this and during the signup - I found out that my imei wouldn't work in Verizon's system so they used one from another phone. He advised that if I wanted to pay for insurance, if I make a claim it could be an issue because the imei numbers won't match up. Seemed like a big red flag to me. So I didn't go through with it. Wonder how others are handling this?
I just switched from the ATT firmware to ARF4 on T-Mobile, but it says there is no update available, while the newest T-Mobile update is ARF7. Does anyone know how to get updates OTA?
zman441 said:
I just switched from the ATT firmware to ARF4 on T-Mobile, but it says there is no update available, while the newest T-Mobile update is ARF7. Does anyone know how to get updates OTA?
Click to expand...
Click to collapse
Right here bro. You'll need to sign up with Sam Mobile first then download it. It's slow but it'll get there in about 4 hours or so
https://www.sammobile.com/firmwares/galaxy-s9-plus/SM-G965U/TMB/download/G965USQU2ARF7/225597/
glensta said:
Right here bro. You'll need to sign up with Sam Mobile first then download it. It's slow but it'll get there in about 4 hours or so
https://www.sammobile.com/firmwares/galaxy-s9-plus/SM-G965U/TMB/download/G965USQU2ARF7/225597/
Click to expand...
Click to collapse
use updato, much faster
Invalid SIM Card
elliwigy said:
use updato, much faster
Click to expand...
Click to collapse
Can someone help me?
I cannot network unlock a T-mobile Samsung Galaxy 9 plus which has never been active on any plan. When I insert my Verizon SIM card a system notification says "Invalid SIM card. Network Locked SIM card inserted".
I want to bring this phone to Verizon where I have an active plan. I don't have a plan with Tmobile and my friend gifted me this phone. I flashed it to Samsung stock firmware and bought an unlock code from DoctorSim. The code applied successfully however the phone doesn't unlock completely and continues to prompt for the unlock code when I insert the Verizon Sim card. When I called Tmobile they said only a phone active for 40 days on their network can be unlocked using the phone app and that my friend would have to call them to unlock the phone.
jon westerman said:
Can someone help me?
I cannot network unlock a T-mobile Samsung Galaxy 9 plus which has never been active on any plan. When I insert my Verizon SIM card a system notification says "Invalid SIM card. Network Locked SIM card inserted".
I want to bring this phone to Verizon where I have an active plan. I don't have a plan with Tmobile and my friend gifted me this phone. I flashed it to Samsung stock firmware and bought an unlock code from DoctorSim. The code applied successfully however the phone doesn't unlock completely and continues to prompt for the unlock code when I insert the Verizon Sim card. When I called Tmobile they said only a phone active for 40 days on their network can be unlocked using the phone app and that my friend would have to call them to unlock the phone.
Click to expand...
Click to collapse
i dont do network unlocks.. you need to pay ur phone off and use the tmobile unlock apk
Sent from my SM-N960U using Tapatalk
I purchase a like-new condition Samsung Galaxy S9+ phone from Amazon Warehouse for international travel coming up in couple days. I figured I would have a better chance of getting an authentic phone from Amazon than from ebay sellers. I received the phone yesterday, and here is the situation with the phone:
- The box of the phone says "unlocked by Samsung"
- The sticker on the back of the phone has the model # SM-G965UZBAXAA and IMEI number of a factory unlocked phone
- The actual IMEI of the phone however shows model # SM-G965UZBAATT, which corresponds to the AT&T carrier locked phone
- When I turn on the phone, it shows T-mobile screen and has T-mobile apps on it
How do I determine whether this is a AT&T phone, or a T-mobile phone or something else? Unfortunately, I do not have either TMO or ATT sim cards that I can use to check which network the phone works on. How do I know whether this phone is unlocked and if it is will work internationally? I am not sure how to explain the imei of the phone coming up with ATT model number, yet the phone shows TMO screen.
Please help as I need to get this resolved today, and don't have time to purchase another phone. Thanks much in advance!!
prince_a1 said:
I purchase a like-new condition Samsung Galaxy S9+ phone from Amazon Warehouse for international travel coming up in couple days. I figured I would have a better chance of getting an authentic phone from Amazon than from ebay sellers. I received the phone yesterday, and here is the situation with the phone:
- The box of the phone says "unlocked by Samsung"
- The sticker on the back of the phone has the model # SM-G965UZBAXAA and IMEI number of a factory unlocked phone
- The actual IMEI of the phone however shows model # SM-G965UZBAATT, which corresponds to the AT&T carrier locked phone
- When I turn on the phone, it shows T-mobile screen and has T-mobile apps on it
How do I determine whether this is a AT&T phone, or a T-mobile phone or something else? Unfortunately, I do not have either TMO or ATT sim cards that I can use to check which network the phone works on. How do I know whether this phone is unlocked and if it is will work internationally? I am not sure how to explain the imei of the phone coming up with ATT model number, yet the phone shows TMO screen.
Please help as I need to get this resolved today, and don't have time to purchase another phone. Thanks much in advance!!
Click to expand...
Click to collapse
put any sim in it and it should work these phones are multi carrier means all the us models are the same if its att imei id say its unlocked since obviously last used was t mobile but if you put any sim in it other than att it should accept it and not say unnsuported sim and or ask for unlock code
to further this as i said the us models are all the same. They have a file called CSC which determines carrier based settings you can put in a tmobile sim and it will repersonalize for tmobile then swap to att and att will show up..
Its the way of the future and actually quite nice as one firmware pretty much covers all carriers other than specific user data which is that carriers apps
it may be unlocked obviously the listing was wrong but xaa is factory unlocked for sims, You can reflash xaa if it is unlocked for non carrier branding,But id put any sim in and see
TheMadScientist said:
They have a file called CSC which determines carrier based settings you can put in a tmobile sim and it will repersonalize for tmobile then swap to att and att will show up..
Click to expand...
Click to collapse
Thanks for your response. So if the previous owner put a T-mobile sim in the AT&T phone, then would it show the T-mobile screen at startup, and also have the T-mobile branded apps?
prince_a1 said:
Thanks for your response. So if the previous owner put a T-mobile sim in the AT&T phone, then would it show the T-mobile screen at startup, and also have the T-mobile branded apps?
Click to expand...
Click to collapse
Yes the csc files are multi carrier the phone will do a New sim inserted please reboot to apply new carrier configuration
and it will reboot and install the inserted sims carrier based bloat apps
TheMadScientist said:
Yes the csc files are multi carrier the phone will do a New sim inserted please reboot to apply new carrier configuration
and it will reboot and install the inserted sims carrier based bloat apps
Click to expand...
Click to collapse
Thanks again! Is it safe for me to do a factory reset on the phone? I wasn't sure if it was rooted and whether a factory reset might brick it. If I do a factory reset, what would it restore to - the AT&T or TMO configuration, or something else?
prince_a1 said:
Thanks again! Is it safe for me to do a factory reset on the phone? I wasn't sure if it was rooted and whether a factory reset might brick it. If I do a factory reset, what would it restore to - the AT&T or TMO configuration, or something else?
Click to expand...
Click to collapse
Yes its safe go into settings and account backup restore it should show factory data reset Thats the proper way to get rig of a google account on the device It will stay as is until a new sim is inserted factory resets have nothing to do with it
TheMadScientist said:
Yes its safe go into settings and account backup restore it should show factory data reset Thats the proper way to get rig of a google account on the device It will stay as is until a new sim is inserted factory resets have nothing to do with it
Click to expand...
Click to collapse
Thank you so much for the information! Highly appreciated!!
TheMadScientist said:
Yes the csc files are multi carrier the phone will do a New sim inserted please reboot to apply new carrier configuration
and it will reboot and install the inserted sims carrier based bloat apps
Click to expand...
Click to collapse
I downloaded the phoneinfo app, and here it what it shows:
Firmware's CSC code: XAA
Active CSC code: TMB
IMEI check shows model ending in: ATT
That made me highly confused as to whether this was a AT&T phone, a T-mobile phone or whether it was originally sold as factory unlocked.
prince_a1 said:
I downloaded the phoneinfo app, and here it what it shows:
Firmware's CSC code: XAA
Active CSC code: TMB
IMEI check shows model ending in: ATT
That made me highly confused as to whether this was a AT&T phone, a T-mobile phone or whether it was originally sold as factory unlocked.
Click to expand...
Click to collapse
So originally it was a att device. Who ever used it used it on tmobile but on xaa which is debloated unlocked
TheMadScientist said:
So originally it was a att device. Who ever used it used it on tmobile but on xaa which is debloated unlocked
Click to expand...
Click to collapse
Under Service Provider SW ver., it shows TMB/XAA/ATT
I am trying to understand what this means, why would it show TMB, XAA and ATT? Does it mean the phone was originally AT&T, then someone installed XAA firmware on it and used it on T-mobile. If that is true, is there a way for me to verify whether the current installed firmware is XAA?
prince_a1 said:
Under Service Provider SW ver., it shows TMB/XAA/ATT
I am trying to understand what this means, why would it show TMB, XAA and ATT? Does it mean the phone was originally AT&T, then someone installed XAA firmware on it and used it on T-mobile. If that is true, is there a way for me to verify whether the current installed firmware is XAA?
Click to expand...
Click to collapse
That is correct. You see it now. The third csc code is the original device. The second is what csc you have running. And the first is or was sim inserted.
Look in settings about phone and software info. At the bottom somewhere it should show you
TheMadScientist said:
That is correct. You see it now. The third csc code is the original device. The second is what csc you have running. And the first is or was sim inserted.
Look in settings about phone and software info. At the bottom somewhere it should show you
Click to expand...
Click to collapse
Yes, what I pasted above is from about phone->software info. It shows the service provider sw version as TMB/XAA/ATT. Thank you!!
Obligatory - This is my first post here, please go easy on me. If this is the wrong section please point me where I need to go.
Okay, I have been having issues getting IMS registration (for att) on my N20U (unbranded) Snapdragon. This is an issue because I don't receive most calls without VoLTE, and the service I am using is actually FirstNet. (An at&t service that provides priority cell tower access for first responders.) Who is also dropping legacy 3G and analogue calling at the end of the year.
The FN sim I was given would not change the network CSC to ATT like it should have in order to work properly.
I was able to get to the manual CSC change menu through the dialer code with a TFW-att sim card (yes, while on oneUI 3.0). I suppose the menu is locked out when other csc's are active.
This allowed me to force change to ATT's csc, then place my FN sim in the phone. The kicker? I had to toggle "do not auto update CSC based on sim data" in the menu to get this method to stick.
Things are grand, working fine, but i got curious as to what options the other csc's had to offer. So i start flipping through the list and end up landing on.....you guessed it..... XAA.
Without thinking about it, i ran it, the phone rebooted, and now im screwed. Flashed the ATT rom with Odin- no change. Factory reset? No change. I messed up BIG.
Finale / TLDR
If you didn't get what just happened there, I used a specific sim card to enable a CSC a menu that uncle sammy does not want you playing with. Proceeded to disable auto CSC changing by SIM, then walked back into a CSC that does not allow me to open said menu. Thus preventing my phone from working fully on ANY NETWORK ever again. With root impossible...
Side notes that failed: Tried fac reset/ tried firmware flash/ tried samkey (no android 11 support)/ tried force change from network side. I hope im not out of options?
****you2dude said:
Obligatory - This is my first post here, please go easy on me.
Click to expand...
Click to collapse
Please check your PM inbox ASAP. Thank you.
-Regards: Badger50
Hey guys, while I am not new to this, it has been several years.
I recently got a used unlocked Comcast/Xifinity S21. I have a T-mobile SIM card.
I tried flashing the rom to stock U1 which worked great but my signal is poor. While connected to Wi-Fi, the mobile networks/Network Operators in settings shows "T-mobile Wi-Fi Calling". But while I am not connected to Wi-Fi, the Network Operators shows Xfinity Mobile.
Under software information, it shows: CCT/CCT/CCT
How I can fix this? I made sure to not click the HOME_CSC when using ODIN, and I even did this twice. Should I just try the U firmware instead? Or was this because I left the USERDATA section blank in ODIN? (I used XAA, and then TMB a second time under Frija to download the files though).
Thank you for your help
Facing the same issue with my unlocked S21 from Xfinity Mobile - now using it on VZW but I can't get Wi-Fi calling to work at all... the toggle for it isn't even there! Haven't found a way to change the CSC.
It doesn't matter the SIM, even an AT&T SIM card displays as "Xfinity Mobile" on this phone!
Update: I was able to use SamKEY to change the CSC to VZW!
Instructions:
You need to buy one credit from a reseller on eBay and download the program on samkey.org
Then turn on Developer Options in Android, and from there, turn on USB Debugging.
Connect your phone to your PC, then run the SamKEY program.
Login with the credentials you obtained from the eBay reseller, put TMB into the "Change CSC (buyer)" box, and click "CHANGE CSC"!
During the process, the phone will ask you to grant permission to your PC, don't forget to allow it (promptly), or else the program will exit, without changing your CSC.
As to which firmware to use, I'm tempted to say the TMB firmware might be the most reliable in your situation?
I'm using the latest VZW "991U" firmware and all the carrier features are working properly now.
quadrun1 said:
Update: I was able to use SamKEY to change the CSC to VZW!
Instructions:
You need to buy one credit from a reseller on eBay and download the program on samkey.org
Then turn on Developer Options in Android, and from there, turn on USB Debugging.
Connect your phone to your PC, then run the SamKEY program.
Login with the credentials you obtained from the eBay reseller, put TMB into the "Change CSC (buyer)" box, and click "CHANGE CSC"!
During the process, the phone will ask you to grant permission to your PC, don't forget to allow it (promptly), or else the program will exit, without changing your CSC.
As to which firmware to use, I'm tempted to say the TMB firmware might be the most reliable in your situation?
I'm using the latest VZW "991U" firmware and all the carrier features are working properly now.
Click to expand...
Click to collapse
Hey thanks for this!
I'm ready to change it but I get a warning using SamKey. Just wanted to see if you got the same warning or not:
"You phone has Special Carrier settings!
ITS NOT RECCOMENDED TO CHANGE CSC ON THIS MODEL.
Because Security area (SEC) may get "Relocked" and NO WAY TO UNLOCK IT again!!!
Are you sure YOU WANT TO CONTINUE CHANGE CSC?"
As you would imagine, just wanted to double check with you and see if you got this same warning or not.
Thanks! If not, I'll try doing a freshwipe and firmware and seeing if I get the same warning.
quadrun1 said:
Update: I was able to use SamKEY to change the CSC to VZW!
Instructions:
You need to buy one credit from a reseller on eBay and download the program on samkey.org
Then turn on Developer Options in Android, and from there, turn on USB Debugging.
Connect your phone to your PC, then run the SamKEY program.
Login with the credentials you obtained from the eBay reseller, put TMB into the "Change CSC (buyer)" box, and click "CHANGE CSC"!
During the process, the phone will ask you to grant permission to your PC, don't forget to allow it (promptly), or else the program will exit, without changing your CSC.
As to which firmware to use, I'm tempted to say the TMB firmware might be the most reliable in your situation?
I'm using the latest VZW "991U" firmware and all the carrier features are working properly now.
Click to expand...
Click to collapse
ignore my last post. I did a fresh wipe and tried again and didn't get that error. The CSC has now changed to TMB and already my signal has shot up. Thank you again so much!
shadowwisp1 said:
ignore my last post. I did a fresh wipe and tried again and didn't get that error. The CSC has now changed to TMB and already my signal has shot up. Thank you again so much!
Click to expand...
Click to collapse
What if I didn't fresh install and continue changing the CSC with this warning? What would happen?
What are the "TMB" and "USC" in the "Update info" links?
They're both US unlocked.
doc.samsungmobile.com/SM-S918U1/TMB/doc.html
doc.samsungmobile.com/SM-S918U1/USC/doc.html
They correspond to the CSC (Consumer software customization) determined by your SIM card. If you're on T-Mobile, you will see TMB. If your'e on US Cellular, you'll see USC. On an Unlocked U1 phone, there may be carrier specific changes with an update.
Guyinlaca said:
They correspond to the CSC (Consumer software customization) determined by your SIM card. If you're on T-Mobile, you will see TMB. If your'e on US Cellular, you'll see USC. On an Unlocked U1 phone, there may be carrier specific changes with an update.
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And if someone changes their service, can the old updates that were for the old carrier pose a potential problem now that they're with the new carrier and receiving their updates?
When you remove the old SIM card and insert the new one, it will ask you to restart to apply the correct settings for your carrier. The SIM does the work for you.
Guyinlaca said:
When you remove the old SIM card and insert the new one, it will ask you to restart to apply the correct settings for your carrier. The SIM does the work for you.
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I assumed that was just changing the APN and changing the carrier settings. But it actually undoes old updates and reinstalls them?
No. Every firmware and update has CSCs built in. It doesn't revert the software, it just activates features specific to your carrier (based on SIM). It's a partition of sorts.
Guyinlaca said:
No. Every firmware and update has CSCs built in. It doesn't revert the software, it just activates features specific to your carrier (based on SIM). It's a partition of sorts.
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1) So when one switches from carrier one to carrier two, what happens to all the past updates that are associated with carrier one?
2) If the SIM card is removed and a new one isn't inserted (for instance if one's upgading to a new phone), will the future updates be "generic"? (Obviously when the old phone is in one's home with a wifi connection.)
1. Each U1 software update contains all US carrier CSC partitions. If you update from A7 to A8, and change SIM cards, you'd remain on A8, but the CSC partition switches to the new carrier. There is never any rolling back, merely switching from one partition to another.
2. If you remove the SIM, your phone updates using the previously set CSC. If you used a T-Mobile SIM, it stays on TMO. The default CSC on U1 is XAA and there's little reason to go back to it, though it can be done with certain tools.
Guyinlaca said:
1. Each U1 software update contains all US carrier CSC partitions. If you update from A7 to A8, and change SIM cards, you'd remain on A8, but the CSC partition switches to the new carrier. There is never any rolling back, merely switching from one partition to another.
2. If you remove the SIM, your phone updates using the previously set CSC. If you used a T-Mobile SIM, it stays on TMO. The default CSC on U1 is XAA and there's little reason to go back to it, though it can be done with certain tools.
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Thank you.