Develop Bugs

[Q] SIM Unlock SGH M919 Outside US which was never activated on Tmobile Network

Hello All,
I got a t-mobile s4 from USA which was paid in full and never activated on any network in USA. I am now trying to use an Airtel Sim Card in India and it shows that its SIM Unlocked. On contacting the T-Mobile support they are saying that they cant provide an unlock code because the device was never activated on their network.
I am stuck because all websites providing unlock codes work on the same precondition that the device was earlier activated in a T-Mobile network. I am also not able to get into service mode and apply the sim unlocking fix as suggested in few posts.
Please provide help and suggest me the options. I am not afraid to shell some more bucks to make it work but i need assurity that the method would work.
Is there a way that i can try which doesnt require t-mobile network at all???
My android version is 4.4.2 and device has been rooted now.

To use service mode to unlock, you need to flash MDL modem first. After unlocking, you should be able to flash the latest modem back retaining the lock.
Have you checked if the region lock away app works?
This thread has some info http://forum.xda-developers.com/showthread.php?t=2654058
Sent from my SAMSUNG-SGH-I337 using Tapatalk

jmjoyas said:
To use service mode to unlock, you need to flash MDL modem first. After unlocking, you should be able to flash the latest modem back retaining the lock.
Have you checked if the region lock away app works?
This thread has some info http://forum.xda-developers.com/showthread.php?t=2654058
Sent from my SAMSUNG-SGH-I337 using Tapatalk
Click to expand...
Click to collapse
Regionlockaway apps doesnt work...I am outside USA having no access to the T-Mobile network and was wondering whether the steps suggested by you will allow me to unlock the device from service mode despite having no cellular service?

gargyagotra said:
Regionlockaway apps doesnt work...I am outside USA having no access to the T-Mobile network and was wondering whether the steps suggested by you will allow me to unlock the device from service mode despite having no cellular service?
Click to expand...
Click to collapse
As far as I know, the service mode unlock disables the carrier check and doesnt require cellular service.
Also, the S4s are also region locked. They get region unlocked when activated and used on the carrier network. So, your phone requires both the sim and region unlock.

jmjoyas said:
As far as I know, the service mode unlock disables the carrier check and doesnt require cellular service.
Also, the S4s are also region locked. They get region unlocked when activated and used on the carrier network. So, your phone requires both the sim and region unlock.
Click to expand...
Click to collapse
Thanks for your response. I am a newbie so just confirming the steps that i need to take to unlock the device:-
a) SInce i am on 4.4.2 with baseband as M919UVUF9B4 i would need to downgrade it to 4.2 stock version using the link you have recommended above.
b) Once i am on the 4.2 version i can then flash MDL modem to sim unlock
c) Then use region lock away tool to region unlock.
d) Upgrade it again to 4.4.2 and use my device freely.
Let me know if i got it right

gargyagotra said:
Thanks for your response. I am a newbie so just confirming the steps that i need to take to unlock the device:-
a) SInce i am on 4.4.2 with baseband as M919UVUF9B4 i would need to downgrade it to 4.2 stock version using the link you have recommended above.
b) Once i am on the 4.2 version i can then flash MDL modem to sim unlock
c) Then use region lock away tool to region unlock.
d) Upgrade it again to 4.4.2 and use my device freely.
Let me know if i got it right
Click to expand...
Click to collapse
For the service menu to work, all you need is the MDL modem. You do not need to downgrade everything. You should be able to find a way to flash the modem alone.

jmjoyas said:
For the service menu to work, all you need is the MDL modem. You do not need to downgrade everything. You should be able to find a way to flash the modem alone.
Click to expand...
Click to collapse
Thanks for confirming. However, i am unable to find any thread tutorial which talks about flashing NB4 modem back to MDL on NB4 bootloader. Most of the threads talk about flashing modems which are prior to 4.3 and doesnt serve my purpose as in am on the latest bootloader.
Please help in providing any thread link or steps to perform the flashing.
Thanks Again!

Question about Network Unlock

Hello all,
I have a Samsung Galaxy S III from AT&T.
I plan on traveling so, I wanted to unlock it. I followed the steps on Android 4.1.1 I believe and it seemed to work (my menus looked identical to the tutorial I followed, but I don't have another SIM to test with). But, I have had the phone for a while and it is really sluggish, so I backed it up and decided to do a hard reset. The phone is running much smoother now, but I did do an AT&T software update which brought it to Android 4.3, and now when I look at the menu after typing *#197328640# and following the steps, when I get to Network Unlock, it looks different. Did the update relock my phone to the AT&T network. Is there a way to verify? Should I just hard reset again and stick with 4.1? Pleas let me know as soon as possible as I am traveling soon.
Thanks for all the help

If your phone was unlocked using any method, it should not relock. You can test it with a non att sim.

audit13 said:
If your phone was unlocked using any method, it should not relock. You can test it with a non att sim.
Click to expand...
Click to collapse
How do I test if I don't have access to a non ATT sim, I have one Korean SIM card, but I don't know how to test with it because it is not currently being serviced.

Put in the non-ATT sim, power up the phone. If it does not ask you to enter an network or carrier unlock code, the phone is unlocked.

audit13 said:
Put in the non-ATT sim, power up the phone. If it does not ask you to enter an network or carrier unlock code, the phone is unlocked.
Click to expand...
Click to collapse
it shows no signal, but does not ask me for a network or a code. So it should be fine right?

[Q] How to determine which carrier I'm locked to when there are no bloatware apps?

I have a Canadian Bell S3 i747m which broke and I got some random guy to fix it for me. He frustratingly ended up installing a ROGERS circuit board(or so he says) without bothering to check the fact my phone was loaded with Bell bloatware or just asking me my carrier.
I now need to unlock the SIM in order to use it properly and I just want to be sure I have the correct information and I don't end up paying for an unlock code that will not work since I didn't provide the proper carrier.
My SIM card (not sure if that matters): BELL
My board/IMEI: ROGERS (Apparently)
I wanted to determine which carrier I was tied to but I see 0 bloatware in my phone which makes me think the guy is wrong/lying and it's not actually a Rogers board. Is there another way to determine which carrier my phone is tied to?

Cyclone112 said:
I have a Canadian Bell S3 i747m which broke and I got some random guy to fix it for me. He frustratingly ended up installing a ROGERS circuit board(or so he says) without bothering to check the fact my phone was loaded with Bell bloatware or just asking me my carrier.
I now need to unlock the SIM in order to use it properly and I just want to be sure I have the correct information and I don't end up paying for an unlock code that will not work since I didn't provide the proper carrier.
My SIM card (not sure if that matters): BELL
My board/IMEI: ROGERS (Apparently)
I wanted to determine which carrier I was tied to but I see 0 bloatware in my phone which makes me think the guy is wrong/lying and it's not actually a Rogers board. Is there another way to determine which carrier my phone is tied to?
Click to expand...
Click to collapse
The carrier doesn't matter. Once unlocked, it's unlocked for every carrier (unless it's unlocked by code).
You could go check the APN to see which carrier it's from.

BWolf56 said:
The carrier doesn't matter. Once unlocked, it's unlocked for every carrier (unless it's unlocked by code).
Click to expand...
Click to collapse
Oh really? I was looking at the gsmliberty site for unlocking and it asks for a carrier. I can't post the link since I'm a new account but here it is split:
gsmliberty(dot)net/shop/samsung-galaxy-s3-unlock-codes-p-3528.html
I then went into their Terms of Service and it specifies that if I provide an incorrect carrier and the unlock code doesn't work then I won't get a refund. Does this mean this site is BS and I should avoid it and find another?
EDIT: Oh I see you added info about checking the APN. Don't know what that is but I'll Google it. Assuming I find it should I still avoid gsmliberty or should I give them a shot?

BWolf56 said:
The carrier doesn't matter. Once unlocked, it's unlocked for every carrier (unless it's unlocked by code).
You could go check the APN to see which carrier it's from.
Click to expand...
Click to collapse
I went to Settings > Connections > More networks > Mobile Networks and it tells me this: Insert SIM card to access network services
EDIT: Ok I finally found the AP and CSC by dialing *#1234# and then comparing it to sammobiles firmware to find out which carrier it is tied to. Still worried about the fact I get the SIM error above but hopefully that will go away when I attempt to unlock it

Cyclone112 said:
I went to Settings > Connections > More networks > Mobile Networks and it tells me this: Insert SIM card to access network services
EDIT: Maybe I'm looking at the wrong spot. Here is my phone's about in case that helps:
View attachment 2807396
Click to expand...
Click to collapse
Umm I though you'd have access to it w/o a sim card.
I'm not sure how else you could determine which carrier the motherboard is locked to.

BWolf56 said:
Umm I though you'd have access to it w/o a sim card.
I'm not sure how else you could determine which carrier the motherboard is locked to.
Click to expand...
Click to collapse
I just ended up editing my last post a minute before you posted this. I did determine the carrier and it is in fact Rogers. I was planning on just getting an unlock code through a website. You mentioned that means it will only be unlocked for them which I'm fine with but I'm just concerned about the fact I have a Bell SIM. Will that cause any problems with the unlock process or future dealings with BELL?
Actually I have a better question. Can I just put Bell's firmware on my phone instead of Rogers using Odin and then get an unlock for Bell and theoretically I'll be back to where I was?

What bootloader is on the phone? If you have the 4.3 bootloader, you'll have to buy an unlock code. If you have the 4.1.1 bootloader and you are running a stock ROM (doesn't matter about the carrier), you can use the free method to unlock it. If you have the 4.1.2 bootloader, downgrade to the Rogers 4.1.1 ROM and unlock it using the free method.

audit13 said:
What bootloader is on the phone? If you have the 4.3 bootloader, you'll have to buy an unlock code. If you have the 4.1.1 bootloader and you are running a stock ROM (doesn't matter about the carrier), you can use the free method to unlock it. If you have the 4.1.2 bootloader, downgrade to the Rogers 4.1.1 ROM and unlock it using the free method.
Click to expand...
Click to collapse
I'm running 4.3 so I know I need an unlock code unfortunately. I have a Bell SIM card but have Rogers firmware. The site I was looking to buy an unlock code from asks for my carrier so I presume I need to use Rogers. Will that be fine or am I able to just throw Bell firmware on my phone and buy an unlock code specifying Bell as my carrier?

I am not sure of you can load the stock Bell firmware and change the phone so it is locked to Bell. If this were the case, owners could switch carriers by flashing different firmware.

Cyclone112 said:
I just ended up editing my last post a minute before you posted this. I did determine the carrier and it is in fact Rogers. I was planning on just getting an unlock code through a website. You mentioned that means it will only be unlocked for them which I'm fine with but I'm just concerned about the fact I have a Bell SIM. Will that cause any problems with the unlock process or future dealings with BELL?
Actually I have a better question. Can I just put Bell's firmware on my phone instead of Rogers using Odin and then get an unlock for Bell and theoretically I'll be back to where I was?
Click to expand...
Click to collapse
Unlocking is permanent and unlocks to every carrier. Knowing which one you're locked to only matters to get a unlock code, after that, it's free for all.

BWolf56 said:
Unlocking is permanent and unlocks to every carrier. Knowing which one you're locked to only matters to get a unlock code, after that, it's free for all.
Click to expand...
Click to collapse
Gotcha, so there's no point in flashing Bell firmware at all. I just need the correct one for getting an unlock code in the first place. Thanks for helping a noob out.

Exynos S9 locked itself to a carrier?

Hey all,
I was given an S9 (Exynos version, unlocked, SM-960F/DS) that had TWRP installed on it, but was stuck in a boot loop. After messing with it for a while, I stuck it in a drawer and forgot about it until recently, when I pulled it out and decided to just restore it to stock. I downloaded a ROM for that specific model from this site ( https://forum.xda-developers.com/galaxy-s9/how-to/official-firmware-thread-regions-t3765015 ) and flashed it using Odin. This got the device to boot fine to the setup, but it defaulted to German, and rejected any SIM I put in it, even though the phone was originally unlocked. So my question is, now how do I remove the SIM lock again? I'm guessing I'll first have to wait the 7 days for the OEM unlock cooldown to elapse again so I can reinstall TWRP?

tattar8 said:
Hey all,
I was given an S9 (Exynos version, unlocked, SM-960F/DS) that had TWRP installed on it, but was stuck in a boot loop. After messing with it for a while, I stuck it in a drawer and forgot about it until recently, when I pulled it out and decided to just restore it to stock. I downloaded a ROM for that specific model from this site ( https://forum.xda-developers.com/galaxy-s9/how-to/official-firmware-thread-regions-t3765015 ) and flashed it using Odin. This got the device to boot fine to the setup, but it defaulted to German, and rejected any SIM I put in it, even though the phone was originally unlocked. So my question is, now how do I remove the SIM lock again? I'm guessing I'll first have to wait the 7 days for the OEM unlock cooldown to elapse again so I can reinstall TWRP?
Click to expand...
Click to collapse
TWRP/Root/Custom has nothing to do with SIM locks, you'd need a sim unlocking service for that

*Detection* said:
TWRP/Root/Custom has nothing to do with SIM locks, you'd need a sim unlocking service for that
Click to expand...
Click to collapse
Then why would the phone start demanding a PUK for any SIM I insert into it after flashing, when it didn't before? The SIMs work on any other phone I try them in.

tattar8 said:
Then why would the phone start demanding a PUK for any SIM I insert into it after flashing, when it didn't before? The SIMs work on any other phone I try them in.
Click to expand...
Click to collapse
Because certain SIM unlocking services depend on you not wiping the phone in order to keep the unlock
You'll need to unlock it again using a paid service

*Detection* said:
Because certain SIM unlocking services depend on you not wiping the phone in order to keep the unlock
You'll need to unlock it again using a paid service
Click to expand...
Click to collapse
The phone was never locked to a carrier -- it was purchased sealed, factory unlocked.

tattar8 said:
The phone was never locked to a carrier -- it was purchased sealed, factory unlocked.
Click to expand...
Click to collapse
In that case check it has not been IMEI blacklisted due to non payment of contract or reported stolen, you state in your OP it was given to you
If it is IMEI blocked there's nothing XDA can do to help you

*Detection* said:
In that case check it has not been IMEI blacklisted due to non payment of contract or reported stolen, you state in your OP it was given to you
If it is IMEI blocked there's nothing XDA can do to help you
Click to expand...
Click to collapse
What I meant by that was that a friend of mine handed it to me to try to fix after he messed with it in TWRP, getting it stuck bootlooping in the process. He had bought it factory unlocked. I checked the IMEI, it's clean. It's demanding PUKs for any SIM I put in it, even though those SIMs work in other phones; I tried a Ting SIM and a Cricket SIM.

tattar8 said:
What I meant by that was that a friend of mine handed it to me to try to fix after he messed with it in TWRP, getting it stuck bootlooping in the process. He had bought it factory unlocked. I checked the IMEI, it's clean. It's demanding PUKs for any SIM I put in it, even though those SIMs work in other phones; I tried a Ting SIM and a Cricket SIM.
Click to expand...
Click to collapse
Well the only thing I can think is to flash a stock firmware for the region you are in, pick a carrier firmware to force the CSC change, Multi-CSC that contains Germany will default back to that if that is what the phone's original CSC was, but I doubt CSC is causing this
O2U CSC (United Kingdom) for G960F is a single CSC, flash it using CSC and not HOME_CSC along with the other 3 sections
But it seems to me this was not originally a factory unlocked handset, it was unlocked by an unlocking service and sold as one
If that doesn't work, pay for an unlocking service

*Detection* said:
Well the only thing I can think is to flash a stock firmware for the region you are in, pick a carrier firmware to force the CSC change, Multi-CSC that contains Germany will default back to that if that is what the phone's original CSC was, but I doubt CSC is causing this
O2U CSC (United Kingdom) for G960F is a single CSC, flash it using CSC and not HOME_CSC along with the other 3 sections
But it seems to me this was not originally a factory unlocked handset, it was unlocked by an unlocking service and sold as one
If that doesn't work, pay for an unlocking service
Click to expand...
Click to collapse
Is there a way I can find out what carrier the phone thinks it's locked to, or would I just have to get SIM cards from around the world and try them?
Can I do this without enabling OEM Unlock (so without letting the phone run for 7 days)?

tattar8 said:
Is there a way I can find out what carrier the phone thinks it's locked to, or would I just have to get SIM cards from around the world and try them?
Can I do this without enabling OEM Unlock (so without letting the phone run for 7 days)?
Click to expand...
Click to collapse
Samsung Phone INFO will tell you the current CSC, but if it defaulted to German either you flashed a German firmware or that is the default CSC
OEM unlock is only needed for custom
Flashing a Multi-CSC ROM such as BTU for United Kingdom will have the greatest chance of it defaulting to it's original CSC

I used that app, and it indeed says the phone's CSC is German, Deutsche Telekom from what I could tell. I tried flashing a number of different FW packages (including the UK and Singapore ones) but it still defaulted to German each time.
I tried going to their unlock page and entering the IMEI, but they have no record of it being sold by them.

tattar8 said:
I used that app, and it indeed says the phone's CSC is German, Deutsche Telekom from what I could tell. I tried flashing a number of different FW packages (including the UK and Singapore ones) but it still defaulted to German each time.
I tried going to their unlock page and entering the IMEI, but they have no record of it being sold by them.
Click to expand...
Click to collapse
Like I said, try flashing a carrier branded firmware like O2U, it cannot default to German if that CSC is not included
Flash using CSC and not HOME_CSC

Sim lock is on its own secure enclave chip, so if this was truly Sim unlocked then it isn't even possible to "relock". Either was unlocked in an unreputable way, or is IMEI blocked as mentioned before.

So I just got time to re-visit this project. I flashed O2U firmware, and it defaulted to English and shows the corresponding CSC. The phone is still locked, and I checked a bunch of IMEI blacklist checkers and each one comes back clean. At this point I accept that the phone is actually locked by a carrier, so I need to instead figure out how to get it unlocked, and to do that I need to figure out what carrier it's locked to. Like I said earlier, I tried entering the IMEI into Deutsche Telekom's unlocking page, and they have no record of them having locked that phone. So how would I go about figuring out what carrier it's locked to? If that information is on its own secure enclave chip, is there any way to read it?

Afaik german providers are forbidden by law to simlock phones for several years already. Problem must be somewhere else.

Try entering the PUK of any SIM if that's what's requested. It should be on the full size SIM, else contact your mobile network operator.

Need help network unlocking, flashed to stock

I got a new phone, the LM-G820UM AT&T version. I followed this guide: https://forum.xda-developers.com/t/tutorial-crossflash-bypass-opid-mismatched-error.4345963/ to flash the stock firmware. With my SIM card in it says "network locked", it doesn't prompt for the unlock code. I have the unlock code and I've tried the various unlock commands (2945#*71001# and 2945#*20001#), but nothing comes up when I do these. Do I need to get it back to the AT&T firmware to be able to unlock it? If so, how can I do this?

gunnerone007 said:
I got a new phone, the LM-G820UM AT&T version. I followed this guide: https://forum.xda-developers.com/t/tutorial-crossflash-bypass-opid-mismatched-error.4345963/ to flash the stock firmware. With my SIM card in it says "network locked", it doesn't prompt for the unlock code. I have the unlock code and I've tried the various unlock commands (2945#*71001# and 2945#*20001#), but nothing comes up when I do these. Do I need to get it back to the AT&T firmware to be able to unlock it? If so, how can I do this?
Click to expand...
Click to collapse
wow, yeah, that's unfortunate. First, yes, it's the at&t firmware that the unlock code works with, not any other firmware.
second, at&t doesn't make their kdz available, so you have no easy way to get back to their firmware.
you might get lucky and find someone who has backed up all their partitions from at&t. Then u would flash ea one back via qfil.
Important lesson: don't buy a locked phone. if u get a locked phone, don't to anything to the firmware until u unlock the phone.
cheers

@AsItLies would this phone work in it's current state with AT&T?

gunnerone007 said:
@AsItLies would this phone work in it's current state with AT&T?
Click to expand...
Click to collapse
To the best of my knowledge, no. At&t is one of the carriers that has restrictions for their networks. Last I read (have never used them personally), they only allow phones that have their IMEI (they check that), and it's using their ROM, to access volte and vowifi.
so, would it work? yes and no. Volte and Vowifi may or may not be important to you.
Additionally, I'm absolutely no expert with at&t, so u might just try and find out, my info could be outdated.