Develop Bugs

Help - Cannot Find Answer on Flashing t-mobile modem on at&t phone

POSTED IN ANY QUESTION THREAD - CAN DELETE THIS AND PLEASE REPLY TO MY Q THERE THANKS - SAME Q JUST FIGURED EASIER TO POST IT THERE
Have a stock non-unlocked (no unlock) at&t phone with 4.2 android.
Could I use the 4.3 "no-knox" modem.bin I see in these forums that's for t-mobile and just ODIN it over top of the at&t 4.2 modem (mdl modem for at&t that came on the phone when it was purchased) and then use CWM to install a t-mobile rom and have the phone work under t-mobile?

drtechnology said:
POSTED IN ANY QUESTION THREAD - CAN DELETE THIS AND PLEASE REPLY TO MY Q THERE THANKS - SAME Q JUST FIGURED EASIER TO POST IT THERE
Have a stock non-unlocked (no unlock) at&t phone with 4.2 android.
Could I use the 4.3 "no-knox" modem.bin I see in these forums that's for t-mobile and just ODIN it over top of the at&t 4.2 modem (mdl modem for at&t that came on the phone when it was purchased) and then use CWM to install a t-mobile rom and have the phone work under t-mobile?
Click to expand...
Click to collapse
Just because someone else is going to find this thread and start getting ideas...
NO!!!!
No one should EVER do this. Never flash a modem that was not SPECIFICALLY made for your SPECIFIC device.

Skipjacks said:
Just because someone else is going to find this thread and start getting ideas...
NO!!!!
No one should EVER do this. Never flash a modem that was not SPECIFICALLY made for your SPECIFIC device.
Click to expand...
Click to collapse
Ok so tell me please what you mean? Do you mean specific device hardware or ???
Because the only difference I see in the 2 phones, At&t S4 and T-Mobile S4 is all in the software for modem and rom. They are 100% identicle in hardware, even being factory set for bands both carriers use. I would never attempt this on Verizon or Sprint S$'s lol - but I am cinfused other than a different modem bin file and different rom, and different model number since its 2 diff companies, what is the difference?
I am confused.
If I cannot do what I noted, then how does one use an at&t phone on a t-mobile network? I am great at flashing modems, roms, recoveries - but my 1st time switching carriers on an exact same model phone. The phone itself is same model far as samsung makes it - only changes to different model when its branded at&t ot t-mobile and uses that companies rom and mode,m files. But isnt the hardware the exact same both places and couldn't the rom and modem files be swapped to allow it to work on the other one's system?
Please help what I need to do - if I cannot do what I asked about then what?

re: tmobile-att
drtechnology said:
Ok so tell me please what you mean? Do you mean specific device hardware or ???
Because the only difference I see in the 2 phones, At&t S4 and T-Mobile S4 is all in the software for modem and rom. They are 100% identicle in hardware, even being factory set for bands both carriers use. I would never attempt this on Verizon or Sprint S$'s lol - but I am cinfused other than a different modem bin file and different rom, and different model number since its 2 diff companies, what is the difference?
I am confused.
If I cannot do what I noted, then how does one use an at&t phone on a t-mobile network? I am great at flashing modems, roms, recoveries - but my 1st time switching carriers on an exact same model phone. The phone itself is same model far as samsung makes it - only changes to different model when its branded at&t ot t-mobile and uses that companies rom and mode,m files. But isnt the hardware the exact same both places and couldn't the rom and modem files be swapped to allow it to work on the other one's system?
Please help what I need to do - if I cannot do what I asked about then what?
Click to expand...
Click to collapse
If the two phones ATT i337 and Tmobile M919 were as identical as you say they are and even use the same bands then
why is the gsm baseband (modem.bin) and the lte modem (non-hlos.bin) different enough not to be interchangeable?
Not even the STOCK 4.3 firmware or any of the zipfile custom roms here in xda are not identical enough
so we would not need to have two different and separate forums for these two phones.
First thing you need to do is to get your phone on the Tmobile network is to unlock it or have it unlocked.
Then you need to get a tmobile sim card and root the phone if it's not already rooted.
You will also need to flash cf-autoroot to root the phone and then flash a custom recovery like cwm or twrp.
Then last but not least you will need to flash a Tmobile custom rom from the Tmobile M919 forum.
None of the custom roms found here in xda contain modem.bin or hlos-bin images.
Those you already have in your phone will work fine even though they are NOT identical.
The two .bin images are setup so the two networks can establish GSM and LTE communications
between your phone and their towers using different bands and different frequencies.
Good luck.

Misterjunky said:
If the two phones ATT i337 and Tmobile M919 were as identical as you say they are and even use the same bands then
why is the gsm baseband (modem.bin) and the lte modem (non-hlos.bin) different enough not to be interchangeable?
Not even the STOCK 4.3 firmware or any of the zipfile custom roms here in xda are not identical enough
so we would not need to have two different and separate forums for these two phones.
First thing you need to do is to get your phone on the Tmobile network is to unlock it or have it unlocked.
Then you need to get a tmobile sim card and root the phone if it's not already rooted.
You will also need to flash cf-autoroot to root the phone and then flash a custom recovery like cwm or twrp.
Then last but not least you will need to flash a Tmobile custom rom from the Tmobile M919 forum.
None of the custom roms found here in xda contain modem.bin or hlos-bin images.
Those you already have in your phone will work fine even though they are NOT identical.
The two .bin images are setup so the two networks can establish GSM and LTE communications
between your phone and their towers using different bands and different frequencies.
Good luck.
Click to expand...
Click to collapse
Thanks Got her phone working ok. So the key was if unlocked, the at&t phone will work on t-mobile even with an at&t modem file on it I knew the 2 companies could be used on the other's network just did not know the modem file works both ways if unlocked. I assumed the hardware is the same on both phones so just flash a tmobile modem lol - I learned I was wrong thanks for ur help. Years of rooting and never had an issue with using one carrier on another carrier's network, was my 1st time
Thanks a lot for your help. Its working great now!

How to Update Android on Unlocked AT&T S3 I747 for MetroPCS/TMobile

Hey guys so I decide to get the SGH-147 AT&T S3 off of ebay for MetroPCS which enabled me to get a 2 year squaretrade warranty. After looking back at it now, I feel it might have been a bad idea since Metro has a MIR 349.99 deal for their S3 version which would mean easier android update since it would be on Metro servers if I'm not mistaken. Anyway I can't return the ebay phone now unless there is some software or hardware problems within 30 days
So my problem
I am stuck on 4.1.1 on Kies and when I check for update, because the phone is based on AT&T servers, it won't work since I'm on Metro. I wanted to see if there is anyway for me to update my phone to 4.3 which is the current version. Although, I've heard some people have 4.3 problems?
If that's not advisable, could y'all tell me how I could atleast get to Android 4.1.2? Also is there a 4.4 update in the works?
I just got the phone today and would like to be running on something better than 4.1.1
should I flash the AT&T phone to a MetroPCS ROM lol, if any of those are actually available, or if I were to flash, should I flash it to Tmobile?

First off, if its I747, you MUST flash only those Roms. No others. Now, that's indeed a nice phone with LTE Antenna.
You really heard correct. The 4.3 upgrade from the carrier (ATT for you) /Samsung has a lot of issues. I wouldn't do it for any reason. Particularly on T-Mo network, you will have severe signal issues as reported by others. In addition, it now flashes an EFuse onto your phone along with locked bootloader and other scary stuff.I really would not do it.
Lastly, XDA is organized by devices. So even though you are a T-Mo/Metro PCS customer, you will have to post on AT&T SGS3 forum over there.
Speaking of Rom update, Please visit Root66 Thread for this device. You will find Rooted version of your Current Rom. Dunno why but he does not have 4.2.x for you. Please do your research someone else must have posted it.
Now speaking to 4.3, yes there is a way to get 4.3 on your phone without the issues I mentioned above. But first you will have to flash a Custom recovery such as CWM or TWRP with the help of ODIN on your phone. Again do your research well. Once those are in place, take a look at this thread. It will provide 4.3 experience without ANY concerns or issues. Read it carefully and then read some more. Good Luck.

Perseus71 said:
First off, if its I747, you MUST flash only those Roms. No others. Now, that's indeed a nice phone with LTE Antenna.
You really heard correct. The 4.3 upgrade from the carrier (ATT for you) /Samsung has a lot of issues. I wouldn't do it for any reason. Particularly on T-Mo network, you will have severe signal issues as reported by others. In addition, it now flashes an EFuse onto your phone along with locked bootloader and other scary stuff.I really would not do it.
Lastly, XDA is organized by devices. So even though you are a T-Mo/Metro PCS customer, you will have to post on AT&T SGS3 forum over there.
Speaking of Rom update, Please visit Root66 Thread for this device. You will find Rooted version of your Current Rom. Dunno why but he does not have 4.2.x for you. Please do your research someone else must have posted it.
Now speaking to 4.3, yes there is a way to get 4.3 on your phone without the issues I mentioned above. But first you will have to flash a Custom recovery such as CWM or TWRP with the help of ODIN on your phone. Again do your research well. Once those are in place, take a look at this thread. It will provide 4.3 experience without ANY concerns or issues. Read it carefully and then read some more. Good Luck.
Click to expand...
Click to collapse
THANK YOU! Looks like I got a lot of phone work to do over the weekend. SO do you think it was good/should I stick with this AT&T S3 or should I try to sell it for a discount and buy a Metro PCS S3? The ebay buyer won't take my phone back unless there is a hardware or software problem inherent to phone...unless I fake one ?

If it was me, I'd keep the phone. Metro's S3 does not have LTE Antenna. You'd have been stuck at lower speeds.

Perseus71 said:
If it was me, I'd keep the phone. Metro's S3 does not have LTE Antenna. You'd have been stuck at lower speeds.
Click to expand...
Click to collapse
Metro's s3 does have lte
As for the OP you can flash at&t or T-Mobile ROMs it really doesn't matter because they are backwards compatible (I have done it) and you can flash 4.3 ROMs if you don't want to take the official 4.3 update which you can easily do with Odin without the need for kies or ota.. Now, I suggest the first thing you do is flash a custom recovery and then experiment with 4.3 ROMs, if you keep having problems flash 4.1.2 roms.. There are some things you need to do though to get 4.3 up and running so I suggest you read up on it first. Good luck my friend!
Sent from my SGH-M919 using Tapatalk

It was my impression he wanted Stock Touchwiz Roms not AOSP.
Thanks for letting me know Metro has T999L

Perseus71 said:
It was my impression he wanted Stock Touchwiz Roms not AOSP.
Thanks for letting me know Metro has T999L
Click to expand...
Click to collapse
I did mean touchwiz ROMs.. And the metro model is t999n which is pretty much a t999l
Sent from my SGH-M919 using Tapatalk

What modem should I flash to use a T-Mobile S4 (m919) on At&t network?

So I have am using already a T-Mobile S4 (m919) on At&t's network... I have already rooted it, flashed Hyperdrive, entered the correct APN, and it works basically well...
Here is what I am wondering, my signal strength seems to be not the best and it makes me wonder, is there a modem, baseband I can flash on the T-mobile version of the S4 that could possibly help it work better on the At&t network... and do so with out making my S4 a paper weight?

abovenbeyond said:
So I have am using already a T-Mobile S4 (m919) on At&t's network... I have already rooted it, flashed Hyperdrive, entered the correct APN, and it works basically well...
Here is what I am wondering, my signal strength seems to be not the best and it makes me wonder, is there a modem, baseband I can flash on the T-mobile version of the S4 that could possibly help it work better on the At&t network... and do so with out making my S4 a paper weight?
Click to expand...
Click to collapse
Any M919 modem. MKL is the newest.

abovenbeyond said:
So I have am using already a T-Mobile S4 (m919) on At&t's network... I have already rooted it, flashed Hyperdrive, entered the correct APN, and it works basically well...
Here is what I am wondering, my signal strength seems to be not the best and it makes me wonder, is there a modem, baseband I can flash on the T-mobile version of the S4 that could possibly help it work better on the At&t network... and do so with out making my S4 a paper weight?
Click to expand...
Click to collapse
Glad someone asked that. I looked for a few hours last night and came up empty(been working an off shift so I might have missed it). I am on 4.2.2 MDL and signal is definitely much weaker than my Active on 4.3 . Has anyone compared modems to see which are better?

pahick said:
Glad someone asked that. I looked for a few hours last night and came up empty(been working an off shift so I might have missed it). I am on 4.2.2 MDL and signal is definitely much weaker than my Active on 4.3 . Has anyone compared modems to see which are better?
Click to expand...
Click to collapse
I can provide anecdotal evidence but nothing real...
MK2 is better.
Also, as for which modem to flash; T-Mobile's MK2 would be the one to flash. I've read you can flash other carrier's modems as long as they are the same version, i.e. AT&T MK2 or T-Mobile MK2... but that just doesn't make sense to me and I wouldn't recommend it. The modem you flash is independent of who your carrier is; you go by what brand of phone you have. If you have the M919 then you flash T-Mobile firmwares/modems/etc regardless of which carrier your bill comes from.

abovenbeyond said:
Here is what I am wondering, my signal strength seems to be not the best and it makes me wonder, is there a modem, baseband I can flash on the T-mobile version of the S4 that could possibly help it work better on the At&t network... and do so with out making my S4 a paper weight?
Click to expand...
Click to collapse
I've encountered the same thing with my M919. Switching between Android 4.3 and 4.4.2 modem.bin files made no difference.
I did notice that when I changed my network preference from 3G/2G to 2G-only, I gained about 10 dBa when the handset fell back to GSM-EDGE mode. It made a big difference. I verified that AT&T only uses band II (1900MHz) for GSM and UMTS in my county, so it wasn't because I switched to band V (850MHz) which seems to have better range. What I find annoying is that the handset isn't dropping down to 2G automatically when reception is poor. It'll stick with 3G even when the signal strength is as low as -107 dBa.
No LTE at the moment since my AT&T MNVO doesn't support it.

I'm thinking of buying an M919, carrier unlocked, to use on ATT, so that I can get a proper recovery and have full access to custom ROMs without the safestrap limitations.
Is it safe to say that:
1. If I buy a T-Mobile S4, and it comes carrier unlocked, it will work fine on the ATT network, including 4G / LTE? Lots of data points suggest this but I haven't heard it explicitly stated...
2. Though I could use the phone as identified as an M919, I really want Play Store to see it as an I337 (ATT version), so I can install some ATT specific apps. Is there any problem flashing a build.prop (available in the ATT threads) with the ATT identifiers & APN info, to enable this?
3. Are there any gotchas I should be aware of? Basically, I just want a phone with unlocked bootloader / kernel so I can play. Not too worried about Knox/warranty.
Any insights would be appreciated!
Marc

Frankenscript said:
I'm thinking of buying an M919, carrier unlocked, to use on ATT, so that I can get a proper recovery and have full access to custom ROMs without the safestrap limitations.
Is it safe to say that:
1. If I buy a T-Mobile S4, and it comes carrier unlocked, it will work fine on the ATT network, including 4G / LTE? Lots of data points suggest this but I haven't heard it explicitly stated...
2. Though I could use the phone as identified as an M919, I really want Play Store to see it as an I337 (ATT version), so I can install some ATT specific apps. Is there any problem flashing a build.prop (available in the ATT threads) with the ATT identifiers & APN info, to enable this?
3. Are there any gotchas I should be aware of? Basically, I just want a phone with unlocked bootloader / kernel so I can play. Not too worried about Knox/warranty.
Any insights would be appreciated!
Marc
Click to expand...
Click to collapse
Will the T-Mobile S4 work on the AT&T network; yes it will work if it's carrier unlocked. I purchased my M919 full price out of contract while I was still on AT&T service. Once I carrier-unlocked I was able to pick up AT&T's 4G/LTE and was even able to make use of the AT&T 3G Microcell device which transmits a 3G cell signal and runs over your WiFi. I now have Net10 Wireless with an AT&T SIM card and I still get 4G/LTE when it's around.
Your second question: I do believe that's all that would be required. I'm not 100% sure if just modifying the build.prop would allow you to use the AT&T-specific apps in the Play Store. I never used them to begin with so I never explored whether or not I could make them work on the T-Mobile firmware. Now, I know this involves more than just a build.prop edit, but a 100% sure way to get AT&T Apps working would be to flash a custom ROM based on AT&T firmware. Being that you have a T-Mobile device and are using it on another carrier's network, always remember; when it comes to Odin especially, flash things meant for the T-Mobile M919 ONLY. It doesn't matter that you use AT&T service, your device needs T-Mobile Modems/stock firmwares/etc.
As far as gotchas... not that I can think of. The M919 has an unlocked bootloader and even with KNOX is very easy to root and use custom ROMS on. If you're not concerned with KNOX then you really don't have to take into consideration any special rooting method, no safestrap junk, etc. Without root, just flash a recovery in Odin and flash away.

I know this thread is a bit old, but the situation is very relevant to me. I just won a S4 M919 on eBay which will be delivered tomorrow. T-mobile has agreed to send me an unlock code. My motivation is to install TWRP recovery which I can't do on the i337. I intend to activate it on Cricket (AT&T network). Is it still true that I should stick with firmware, ROMs, and modems designed for the M919? I don't care about AT&T or T-mobile apps so that's not an issue. Basically, I want the best data rates available. Any gotchas that I need to be aware of?

flroots said:
I know this thread is a bit old, but the situation is very relevant to me. I just won a S4 M919 on eBay which will be delivered tomorrow. T-mobile has agreed to send me an unlock code. My motivation is to install TWRP recovery which I can't do on the i337. I intend to activate it on Cricket (AT&T network). Is it still true that I should stick with firmware, ROMs, and modems designed for the M919? I don't care about AT&T or T-mobile apps so that's not an issue. Basically, I want the best data rates available. Any gotchas that I need to be aware of?
Click to expand...
Click to collapse
@flroots
Basically, you're best off bringing the phone to current M919 stock through ODIN. Is that NK2 or has there been a more recent version? I've lost track. But do the entire phone, and in fact as you will see from some threads it is often necessary to flash it twice in succession to get everything to stick. This will bring you to the latest modem. Remember, the modem is two parts: the modem.bin (also known as the gsm modem, which isn't specifically dependent on the bootloader version you have) and the LTE modem (non-hlos.bin, which is dependent on the firmware version, and bad things happen if you mismatch).
Since your phone is out of warranty, there's no downside to going to the latest, even if the phone arrives with 4.2.2 firmware (pre-knox). Tripping the knox bit is only a problem if you would be sending the phone in for warranty service.
I've got the M919 and am using it on ATT, with no problems. I've got the pre-knox firmware (MDL), and will be updating to the latest next time I flash.
Here is an old, but still relevant, thread about my experiences with M919 on ATT.
http://forum.xda-developers.com/galaxy-s4-tmobile/help/using-t-mobile-m919-att-network-t2880349
You will have to configure your APN to match your Cricket service. Sorry, can't help you with those settings but I'm sure they are on XDA somewhere!
Marc

Frankenscript said:
@flroots
Basically, you're best off bringing the phone to current M919 stock through ODIN. Is that NK2 or has there been a more recent version? I've lost track. But do the entire phone, and in fact as you will see from some threads it is often necessary to flash it twice in succession to get everything to stick. This will bring you to the latest modem. Remember, the modem is two parts: the modem.bin (also known as the gsm modem, which isn't specifically dependent on the bootloader version you have) and the LTE modem (non-hlos.bin, which is dependent on the firmware version, and bad things happen if you mismatch).
Since your phone is out of warranty, there's no downside to going to the latest, even if the phone arrives with 4.2.2 firmware (pre-knox). Tripping the knox bit is only a problem if you would be sending the phone in for warranty service.
I've got the M919 and am using it on ATT, with no problems. I've got the pre-knox firmware (MDL), and will be updating to the latest next time I flash.
Here is an old, but still relevant, thread about my experiences with M919 on ATT.
http://forum.xda-developers.com/galaxy-s4-tmobile/help/using-t-mobile-m919-att-network-t2880349
You will have to configure your APN to match your Cricket service. Sorry, can't help you with those settings but I'm sure they are on XDA somewhere!
Marc
Click to expand...
Click to collapse
Thanks a lot for that update. As I understand it, the current firmware is NB4 according to this site:
http://galaxys4root.com/galaxy-s4-stock-firmware/
Not sure what your reference to NK2 is? That doesn't seem to correspond to either 4.2.2 nor 4.4.2? I'm currently on Cricket with a S4 I337 and hope to move the SIM over as soon as my M919 arrives tomorrow.

I believe after NB4 there was NH7 then NK2. Check the firmware thread in the general section for details / links.
Sent from my SGH-M919 using Tapatalk

@flroots
How did this work out for you? I want to do the same thing you said you where going to do.
flroots said:
I know this thread is a bit old, but the situation is very relevant to me. I just won a S4 M919 on eBay which will be delivered tomorrow. T-mobile has agreed to send me an unlock code. My motivation is to install TWRP recovery which I can't do on the i337. I intend to activate it on Cricket (AT&T network). Is it still true that I should stick with firmware, ROMs, and modems designed for the M919? I don't care about AT&T or T-mobile apps so that's not an issue. Basically, I want the best data rates available. Any gotchas that I need to be aware of?
Click to expand...
Click to collapse

Robert417919 said:
@flroots
How did this work out for you? I want to do the same thing you said you where going to do.
Click to expand...
Click to collapse
Robert417919,
I use my SGH-M919 on an AT&T network also. I use the OK3 modem firmware and it seems to work great here. Although I am in Alaska, so top speeds of LTE are only about 6 Mbps where I live. Usually I can only get about 3 Mbps due to the lack of coverage around here.
You can either update to the latest OH3 firmware on your phone, or if you have an old model, with the MDL bootloader, you could also use this guide by lordodin912:
http://forum.xda-developers.com/galaxy-s4-tmobile/general/foh3-modem-bin-mdl-bootloader-t3191094
Also, if you are looking for good roms, you can always check out SlimLP:
http://forum.xda-developers.com/galaxy-s4-tmobile/development/rom-slimlp-jfltetmo-t3377731
Or Resurrection Remix:
http://forum.xda-developers.com/gal...ent/rom-resurrection-lollipop-v5-4-5-t3115155
Hope that helps!

Thanks, this does help out, and another quick question. Are you able to use wifi calling?
AlaskaLinuxUser said:
Robert417919,
I use my SGH-M919 on an AT&T network also. I use the OK3 modem firmware and it seems to work great here. Although I am in Alaska, so top speeds of LTE are only about 6 Mbps where I live. Usually I can only get about 3 Mbps due to the lack of coverage around here.
You can either update to the latest OH3 firmware on your phone, or if you have an old model, with the MDL bootloader, you could also use this guide by lordodin912:
http://forum.xda-developers.com/galaxy-s4-tmobile/general/foh3-modem-bin-mdl-bootloader-t3191094
Also, if you are looking for good roms, you can always check out SlimLP:
http://forum.xda-developers.com/galaxy-s4-tmobile/development/rom-slimlp-jfltetmo-t3377731
Or Resurrection Remix:
http://forum.xda-developers.com/gal...ent/rom-resurrection-lollipop-v5-4-5-t3115155
Hope that helps!
Click to expand...
Click to collapse

Robert417919 said:
Thanks, this does help out, and another quick question. Are you able to use wifi calling?
Click to expand...
Click to collapse
Glad to help, and no, unfortunately not.
-AlaskaLinuxUser
https://thealaskalinuxuser.wordpress.com

[Q] Where is this 4.4.2 modem people keep referring to?

I flashed the Root66 KitKat update for Wind Mobile using Odin. As I was looking through the settings I noticed there were no APNs set. I googled for Wind's APN configuration and manually entered them (before I even tested data, perhaps it was working regardless).
So far I've seen a number of mentions warning against flashing the 4.4.2 modem before flashing the 4.4.2 firmware update. However, I've yet to see the modem posted anywhere. The most recent one in the baseband thread was for 4.3. What am I missing?

Normally 4.3 modem will be working for 4.4 too but you should not have older modem then 4.3
Sent from my SGH-T999 using Tapatalk

It hasn't been posted for that same reason, so nobody will attempt to flash.. Anyone can make a flashable zip for the modem, that it why we are letting people know what happens when you try to flash on older firmware
Sent from my SGH-M919 using Tapatalk

Ill still post the modems in the near future, but wanted to first get that warning out so as many people as possible already know about it when I do. Flashing the 4 4.2 modem on 4.3 firmware has bricked quite a few devices in the Spirit and AT&T forums already. And despite all our efforts, we have yet to get the debrick method to work
That said, if you have a need for the modem, ill get it for you as soon as I can.
And just fyi, after updating to 4.4.2, you cannot use any older modems. They won't brick the device, but you won't have a working radio/signal.

DocHoliday77 said:
Ill still post the modems in the near future, but wanted to first get that warning out so as many people as possible already know about it when I do. Flashing the 4 4.2 modem on 4.3 firmware has bricked quite a few devices in the Spirit and AT&T forums already. And despite all our efforts, we have yet to get the debrick method to work
That said, if you have a need for the modem, ill get it for you as soon as I can.
And just fyi, after updating to 4.4.2, you cannot use any older modems. They won't brick the device, but you won't have a working radio/signal.
Click to expand...
Click to collapse
Heya Doc
I have a Gs3 T999v from Videotron and have been running the 4.3 modem since early this year. I'm currently running CM11 4.4.4.
I was wondering if it would be possible to provide a link for their 4.4.2 modem so I can give it a shot. I know I won't be able to come back from it, but reception with the 4.3 has not been that hot and I've been meaning to get those kinks out. Also since the phone is nearing the end of it's life, at least to me, I don't mind the extra risk. Even if it should technically be entirely safe to do so since i'm running 4.4.2+
Cheers!

[Q] Change baseband version from CA to US on S3 i747

I just bought a Samsung Galaxy S3 i747 from Amazon. It is an unlocked GSM version.
Problem is it has a Canadian baseband version, and I am in the US on AT&T.
I have a problem with data connectivity, and according to Samsung tech support, it is because of the Canadian firmware/baseband version.
Can I change the firmware/baseband version from Canadian build to US build?
If so, how would I do it?
Thank you for any help.

What is the ROM and baseband on your phone? Can you make phone calls?

I could be wrong, but based on my experience with the T999, that shouldn't be working. While flashing a T999V baseband won't hurt it, it simply won't work.
Please tell us your current baseband, current rom, and current firmware build. Enter this in terminal emulator to determine base firmware build,
getprop ro.bootloader
Also, can you verify by the sticker under the battery that it is an I747 and not an I747M?
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DocHoliday77 said:
I could be wrong, but based on my experience with the T999, that shouldn't be working. While flashing a T999V baseband won't hurt it, it simply won't work.
Please tell us your current baseband, current rom, and current firmware build. Enter this in terminal emulator to determine base firmware build,
getprop ro.bootloader
Also, can you verify by the sticker under the battery that it is an I747 and not an I747M?
Sent from my SAMSUNG-SGH-T999 using Tapatalk
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Yes, I can make phone calls. I get 4G data connection, but it is slow and keeps dropping, even though it still shows 4G.
If I swap the sim to my old phone, all data connections work great, so I know it's not the sim or the network.
It is in fact an i747M
device name: SGHi747M
Android version: 4.3
Baseband version: I747MVLUEND2
Kernel version: 3.0.31-2140838
[email protected]#1
Sat Apr 12 21:40:34 KST 2014
Build number: JSS15JI747MVLUEND2
SE for Android status: Enforcing
SEPF SGH-I747M 4.3 0029
From getprop ro.bootloader:
I747MVLUEND2
[email protected]
Thanks!

Ok! Everything looks like it should. You could try updating to the 4.4.2 build, but keep in mind you cannot go back to 4 3 afterwards. (You can flash older ROMs but not firmware). And do not flash a 4.4 2 modem on what you are running now.
You can flash the ROMs built for the i747, but for the modem you can only use the I747M.
If the store you got it from told you it was an I747, you might be able to return or exchange it due to incorrect listing.
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DocHoliday77 said:
Ok! Everything looks like it should. You could try updating to the 4.4.2 build, but keep in mind you cannot go back to 4 3 afterwards. (You can flash older ROMs but not firmware). And do not flash a 4.4 2 modem on what you are running now.
You can flash the ROMs built for the i747, but for the modem you can only use the I747M.
If the store you got it from told you it was an I747, you might be able to return or exchange it due to incorrect listing.
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It was sold as an i747, not i747M, so I will just return it.
The modem is what connects me to the network, so if it remains the Canadian version, changing the firmware won't solve my issue, right?
Thank you for your help!

All I can say on that is you should never flash any firmware that is for any other model device. Its just not safe to do and will almost always cause a hard brick.
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---------- Post added at 05:16 PM ---------- Previous post was at 05:10 PM ----------
So basically, if you're unable to use it as it currently is, I personally think the best option would be to return it and try to get the US I747 model. If you go in and try changing the firmware and it ends up bricking, you'd probably lose the ability to return it, so IMO its just not worth the risk.
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I am going to send it back tomorrow. I don't want to have to flash anything. It should have worked right out of the box, so I'll just return it.
Strange that the Canadian version didn't work as it should. I have an HTC Desire A8182 that is a Telus version, unlocked, and it works just fine on AT&T. No data issues at all. I rooted that one as it only has 100MB internal memory, and I wanted to get rid of bloatware and use Link2SD plus to move apps to the SD card.I didn't use a custom rom, just rooted stock firmware. It's still running 2.2 FroYo, and I love it! It's only 3G, and a tad small, which is why I decided to go with the S3.
Thanks again for your help!

Seemed a little odd to me as well, but there have been a lot of upgrades and enhancements done to many US networks that may not have been done in Canada. Its just a theory, but I747 firmware may have been built to take advantage of that and the I747M might be made to work better with older or just different networks. Kinda hard to explain what I'm thinking here...
Its also possible that the US and Canadian 3g networks are more similar than their 4g ones, which might explain the different experience with your older device.
And then again, you might have simply received a device that had something wrong with it, which you'd want to return anyway I'm sure.
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DocHoliday77 said:
Seemed a little odd to me as well, but there have been a lot of upgrades and enhancements done to many US networks that may not have been done in Canada. Its just a theory, but I747 firmware may have been built to take advantage of that and the I747M might be made to work better with older or just different networks. Kinda hard to explain what I'm thinking here...
Its also possible that the US and Canadian 3g networks are more similar than their 4g ones, which might explain the different experience with your older device.
And then again, you might have simply received a device that had something wrong with it, which you'd want to return anyway I'm sure.
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I sent it back today and the seller will refund me when they receive it.
I found an interesting tidbit on the AT&T forum regarding the S3.
"The international edition won't support LTE bands"
Ordered a US version (presumably, lol) today.