Downgrade M919V from 6.0 to 4.4.2 to SIM unlock? - T-Mobile Samsung Galaxy S 4

My GF's M919V is rooted and is currently running Resurrection Remix, which has been flawless. I'd like to SIM unlock this phone but the usual service menu codes mentioned here do nothing. Is it safe to downgrade to 4.4.2 to do the SIM unlock?

The service menu unlock method only works with the stock Samsung dialler in 4.1.1. If the phone is running a 4.4.2 bootloader, you can't downgrade to 4..1.1. You may be able to unlock the phone using the regionlockaway app on a rooted stock rom and older modem.
This thread may help: http://forum.xda-developers.com/showthread.php?t=2780006
If the 919 s4 is like the i337m s4, you may be able to flash a stock ROM, flash a 4.2.2 modem, root, run regionlockaway, flash original modem, and phone will be unlocked.
As an alternative, you could flash back to a stock rom and buy an unlock code.

Related

[Q] Can you flash Koodo SGH-I747M with AT&T's Kit-Kat?

I unlock both my Koodo SGH-I747M by following the instructions (just by punching a bunch of codes) from one of those YT video and I've been using T-Mobile's prepaid service since.
http://forum.xda-developers.com/galaxy-s3/general/american-canadian-sgs3-read-flashing-t1757755
Since the specs are all the same for SGH-I747M (AT&T/Telus/Bells/Koodo/Rogers) + my phones are unlock, does that mean I can flash both my phones with Kit-Kat (once released) by any of these carriers (AT&T/Telus/Bells/Koodo/Rogers)?
Thanks.
p/s currently still on the original 4.1.1
I would not do it as att and koodo use different bootloaders and modems.
audit13 said:
I would not do it as att and koodo use different bootloaders and modems.
Click to expand...
Click to collapse
Glad I asked first, thanks for the reply and it makes sense :good:.
Personally, I would avoid knox as most custom KK ROMs will work fine with the 4.1.2 bootloader. I would only upgrade the bootloader if it was required for a ROM I really wanted to use.
Your unlock means nothing to the ability to install a ROM or not.
Now, you can install the Samsung ported Sprint Kitkat ROM for AT&T if you update your bootloader and modem to the MK5 version and never use ODIN or try to downgrade your bootloader ever again ! This ROM will not work without the MK5 bootloader and modem. If you proceed that way, your warranty will be void
Also, you can always flash Koodo builds
If you wish to keep your current bootloader, you can always install any of the non samsung ROMs, but some will require that you have the MF1 bootloader at the least (CM for example).

[Q] Unlocking I747 running CM11

Hello all,
I'm new to this forum but not all new to the world of phones/rooting/flashing and all that good stuff. I was looking for a way to unlock the i747 so I can use it with different carriers when traveling abroad. The only thing that I found was unlocking it with the stock 4.1 firmware. Is there a way to unlock it while running CM11 or would I have to flash a stock 4.1 ROM and unlock it that way? Also, if I do revert to stock 4.1 and unlock it, when I flash back CM11 will that void the unlock? Thanks for the help!
You cannot unlock the phone using the free method if you have the 4.3 bootloader on your phone. This is due to the fact that you cannot downgrade the bootloader to the stock 4.1.1 bootloader.
Unlocking is permanent. Flashing won't re-lock.
You have to be stock with a stock dialer. But if you have ever updated your firmware/bootloader to 4.3 or later it will not work.
is it true? i have a i747 on cm11 4.4.4, now i thought i just had to pop a tmobile sim and bam!
DBugg said:
is it true? i have a i747 on cm11 4.4.4, now i thought i just had to pop a tmobile sim and bam!
Click to expand...
Click to collapse
Is your phone unlocked? If it is, you may only get 2g on your i747m until you enable AWS.
My phone is deff still locked to AT&T and i have to unlock it soon. Any way to do this now that my phone is 4.4.4?
Sent from my Carbon-i747 running 4.4.4 with custom mods
Will you be unlocking the phone using an unlock code? Is the phone running a stock ATT ROM?
audit13 said:
Will you be unlocking the phone using an unlock code? Is the phone running a stock ATT ROM?
Click to expand...
Click to collapse
I could prob get it from AT&T customer care before I switch jobs.. I'm on an aosp rom, carbon
Sent from my Carbon-i747 running 4.4.4 with custom mods
adroidgalaxy said:
I could prob get it from AT&T customer care before I switch jobs.. I'm on an aosp rom, carbon
Sent from my Carbon-i747 running 4.4.4 with custom mods
Click to expand...
Click to collapse
You need to be running stock or close to stock in order to enter the unlock code.
If you are running a custom ROM, you may not be prompted to enter the code when you insert a non-AT&T sim.
audit13 said:
You need to be running stock or close to stock in order to enter the unlock code.
If you are running a custom ROM, you may not be prompted to enter the code when you insert a non-AT&T sim.
Click to expand...
Click to collapse
Yep. Stock ROM is the only way you can carrier unlock the phone.
bloodstorm666 said:
Yep. Stock ROM is the only way you can carrier unlock the phone.
Click to expand...
Click to collapse
Apparently, having a working stock dialler on a custom ROM will also prompt for an unlock code. I can't confirm this as I have never used an unlock code on an s3.

[Q] Downgrade 4.4.2 to 4.1.1 to unlock

Is it possible to downgrade from 4.4.2 to 4.1.1 to unlock the device?
You just flash the 4.1.1 then probably have to flash your bootloader if it doesn't boot and then flash the jl2 radio
Hi, I have a custom rom, the galaxy project 4.4.2. What I need to do to unlock the phone?
Can I downgrade to a custom 4.1.2 via recovery, and apply the unlock tutorial?
Correct me if I'm wrong, It's the bootloader that has to be downgraded in order to unlock using the hidden menu. But with devices that took OTA updates 4.3 or later, downgrading bootloader will brick the phone. I'm also looking for an unlock option but no luck so far because my Note 2 has OTA 4.4.2. Does anyone have better information about this?

Can I flash stuff after unlocking my phone?

What if i used regionlock app to unlock my phone (i had to root flash 4.2.2 modem and use regionlock app then flash back to 4.4.2 modem to do this) can i still update to latest firmware or flash roms and modems and will i still be able to keep my phone unlocked?
Once the phone is sim unlocked, it will remain unlocked after flashing modems, bootloader, and ROMs.

stock s3 i747 4.1.2, what should I do first? I want update, root, xposed in the end

Hi there, just factory reset my i747 s3 att phone. i am on 4.1.2.
Should I root first with chainfire easily or should I update first? I dont even remember how to update this phone from stock. I would like to be at 4.4.2 or above (or are any of the newer versions good, 5/6 etc?) with root and xposed installed in the end. What should be next steps be?
thanks!
Moved to Q&A
If the phone is not sim unlocked, I would flash a stock 4.1.1 ROM from sammobile.com using Odin and use the free method to sim unlock. I would then run OTA updates until the phone is running the latest stock ROM. Running OTA updates is the slowest but easiest method to get the phone running the latest modem and bootloader. Many recent custom ROMs require the latest bootloader and modem to function.

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