Develop Bugs

sim unlock and custom roms and or radio upgrade effects?

Hey folks. I'm really tempted to get the T-Mobile S4, have it unlocked so I can take it to AT&T but I know at some point I'll be doing custom roms and probably radio upgrades since they come out once in a while. But will doing any of that break the SIM unlock? The one I fear most is probably radio upgrades but I've never moved a phone to another carrier so don't know all of the implications. Roms I doubt will be an issue but anyone know or have previous experience? At worse I have to keep calling T-Mobile to get it unlocked again if radio upgrades mess it up but I'd rather not be calling them all the time and if it is a problem then maybe I need to rethink this a bit more.

No, when you unlock it, it will be permanently unlocked, even you restore to stock rom, flash any other rom, radios, recovery or anything to OS or software related.
Before you flash a rom, make sure to try it in another provider with the factory/stock version, so you can make sure that the phone is working fine since the beginning,
T-Mobile S4 (SGH-M919) has a lot to offer in connectivity such as LTE Bands 1/2/4/5/7/17; in HSPA+/UMTS: 850/AWS/1900/2100MHz and finally GSM: 850/900/1800/1900MHz, so it surely will work on the AT&T network.
While the AT&T S4 (SGH-I337) only has LTE: Bands 1/4/7/17; HSPA+/UMTS: 850/1900/2100MHz; GSM: 850/900/1800/1900MHz.
For unlocking your T-Mobile S4, here is the link to the new T-Mobile Unlocking Policies: http://support.t-mobile.com/docs/DOC-1588. I bought my new S4 recently and they declined to unlock it before the first 40 days (postpaid) and before the first 60 days (prepaid) and there are certain other requirements to comply.
Lucky for me I found a trick on this forum to unlock it without the subsidy code (since my requests were rejected), it worked flawlessly and even I restore or flash any stock or custom rom, the unlocked state stays permanently because it's based on the NV system, just don't mess up with the NV base system.
If you want a phone with full LTE bands coverage, go for the M919 and it's bootloader unlocked from factory unlike the AT&T version which is bootloader locked. So, you can't go wrong with this model.
In terms of performance, the international version I9500 (without LTE support) is faster than any other S4 with SnapDragon 600 processor, I tested it myself since I have both I9500 and M919, the I9500 is octa-core (4-core of 1.6, and 4-core of 1.2) but only 4-cores work at the same time, in order to have a better power management, but even works in 1.6, it's a little bit faster than the 1.9 from SD600, i noticed on the graphics performance too.
And custom roms and other mods will come thru time for this specific model, just be patience, I have my M919 working with a non-US carrier sim card and installed custom rom Wicked v2 and it's working fast and stable.
I hope this info help you to decide!
Cheers!
Screwbal said:
Hey folks. I'm really tempted to get the T-Mobile S4, have it unlocked so I can take it to AT&T but I know at some point I'll be doing custom roms and probably radio upgrades since they come out once in a while. But will doing any of that break the SIM unlock? The one I fear most is probably radio upgrades but I've never moved a phone to another carrier so don't know all of the implications. Roms I doubt will be an issue but anyone know or have previous experience? At worse I have to keep calling T-Mobile to get it unlocked again if radio upgrades mess it up but I'd rather not be calling them all the time and if it is a problem then maybe I need to rethink this a bit more.
Click to expand...
Click to collapse

Have some question Help Pls

Hi all,
I just got a N900T which is sim unlocked
Device status is official
android version 4.3
baseband version is n900tuvubmi7
kernel version is 3.4.0-1670611
built number is jss15j.n900tuvubmi7
I personally have H2O service and would like to use this On H2O, what sort of steps I will have to do to upgrade this to the newer version of kitkat, root it, and possibly upgrade the modem to take advantage of ATT LTE, and a ROM which is provider neutral, deblouted, stable and fast.
Ill appreciate any help

liquidy said:
Hi all,
I just got a N900T which is sim unlocked
Device status is official
android version 4.3
baseband version is n900tuvubmi7
kernel version is 3.4.0-1670611
built number is jss15j.n900tuvubmi7
I personally have H2O service and would like to use this On H2O, what sort of steps I will have to do to upgrade this to the newer version of kitkat, root it, and possibly upgrade the modem to take advantage of ATT LTE, and a ROM which is provider neutral, deblouted, stable and fast.
Ill appreciate any help
Click to expand...
Click to collapse
Step 1: Chainfire Auto Root to root your phone
http://forum.xda-developers.com/showthread.php?t=2466423
Step 2: RegionLock Away to SIM unlock it
http://forum.xda-developers.com/showthread.php?t=2470551
As for upgrading the modem, I don't think it's necessary.
This is from the thread that discusses using the T-Mobile Note 3 on AT&T:
http://forum.xda-developers.com/showthread.php?t=2464498
Will LTE work on AT&T?
Many people have confirmed that LTE works. There is no speed difference between an AT&T branded phone and the Note 3. Documents obtained from the FCC and also on T-Mobile's site say it supports the frequencies used by AT&T. Do NOT give AT&T your IMEI to your Tmobile Note 3. If you do, AT&T's system will remove your LTE data even though it works perfectly. Give them another AT&T Android IMEI if you have to or if you are coming from an Android phone don't even talk to them. Just remove the SIM in your old phone and put it in your new phone. If you mess up and give them the IMEI some people have gone to the store and gotten the IMEI off the demo unit then gone home and called ATT to change the IMEI. You can also get an AT&T Android LTE IMEI from a family member or friend's phone. It will not effect their service in any way. One user also reported explaining the issue to a rep that changed the default plan and manually made it a plan with LTE. I'm not sure that a lot of reps on AT&T's front line know how to do this though.
What APN settings will my Note 3 need for AT&T and MVNO's?
NAME: ATT Phone
APN: phone
MMSC: http://mmsc.mobile.att.net
MMS proxy: proxy.mobile.att.net
MMS port: 80
MCC: 310
MNC: 410
APN type: default,mms,supl,hipri
Then go to the home screen menu setting, more networks, mobile networks, network mode and change to LTE/WCDMA/GSM.
Although, you might want to try the settings that H2O has on their website to see which one gives you better speeds:
https://www.h2owirelessnow.com/mainControl.php?page=dataManualConfig
Step 3: Install ROM of your choice. My recommendation, Hyperdrive ROM. It gives you Aroma installer, which lets you customize basically every aspect of your install. http://forum.xda-developers.com/showthread.php?t=2709867
I hope this gives you the info you need to get up and running.

Thanks a Million

[Q] No sim detected

Hay guys i just recently flashed my g2 ls980 with stock zve firmware. Everything us working fine except that sim is not being detected no matter what i try. I am really confused as i am a total newbie and am unable to understand technical stuff.

With stock ZVE (that's pure Sprint stock) which SIM are you referring to because with that stock ROM on the Sprint G2 the only SIM card that will ever be recognized at all will be one from Sprint to enable LTE network support.
So... I don't like to assume things, hence the question: what SIM card are you talking about?
The LS980, aka the Sprint G2 variant and the same phone I have, is network locked aka SIM locked to Sprint only if you're running a pure stock ROM which is exactly what ZVE is. The only ways to get the SIM unlocked for other network operation would be a) do a somewhat complicated set of tasks to get it to work (not worth the hassles really and certainly beyond your admitted "newbie" status with respect to this level of tech) or b) install a custom ROM like CloudyG2 (the name just changed today, prior it was known as CloudyG3 but that confused people with the LG G3 and they were trashing their phones trying to install it - it's a G2 ROM ported from the actual G3).
There are other ROMs as well that unlock the LS980 for GSM operation aka regular SIM cards, you may end up using one of them to get proper GSM functionality - LTE support is spotty depending on the networks in your area and the Sprint G2 only supports a few LTE network bands.

Thank you very much for your reply @br0adband. I was able to use my GSM (telenor) sim again but i encountered some problems. Here is the link to my post:
http://forum.xda-developers.com/general/xda-assist/lg-g2-ls980-t3009569
Really sorry for creating a new post as i was unable to find this post in search

Hi I have a few questions about using a phone made for another neterwork (att) on tmo

Well in short I have an At&t Model GS4 the i337 its currently unlocked running on stock Nj4 and of course want to root it. First of all i suspect i need to use t mobile roms now that i am on that network.
Here is a list of questions and links are also appreciated as answers anything that helps!
First and foremost how should i root this (my last device was a G3) so if things are different please tell me also, I their an app or a thread you can point me to.
Secondly how do i update it to a v5.1 or the latest so updating them rom later is not a problem if i must use odin to do this (i want to use the latest to use odin the least)
Lastly anyone who can give directions on how to root and get to the latest version of android i wold greatly appreciate the time anyone spend to respond to this this post i TYIA
So any links that will work work with NJ4 I would be so happy I have only experience with the G3 I feel i know what to do with it but the Gs4 is new to me and i appreciate any help i receive/
Thank yo for reading this and TYIA for responding thank you for your help i hope its as simple as someone posting some links so i can do this easy i again thanks for leading me through the fog and TIA

@BeatnikBandit :
Basically, you're in the wrong forum. You'll need to get support fir the ATT version i337 over in the forum for that model. I used to have one, actually. I sold it on Swappa and got a T-Mo M919 S4 so that I could take advantage of all the AOSP ROMs for the M919. At least as of a year ago, there was no way to unlock the boot loader on the i337 and the only ROMs available for it were basically just skins on the TouchWiz kernel. ROMs, such as they were, used something called SafeStrap. Not sure if things have changed for that device in the year since I gave it up.
You can only use ROMs made for your model. So, even if the locked boot loader weren't an issue with the i337, its hardware is different from the Verizon or T-Mo variants. Using a ROM for a different model will give problems. On the T-Mo M919, there's a bit of an exception in that we're hardware comparable to the international variant, so we can often use ROMs for that one (9505 I think). Oh, and the M919 never got an official lollipop upgrade from T-mo before they gave up on it, so there are some issues with using LolliPop ROMs on the M919.
I'm sorry I can't help you with how to root, but presumably you will find that answer over in the i337 forum.
As for using the i337 on T-Mo, that should be easy enough. Just go in and enter the APN information for T-Mo (probably is in the T-Mo forum somewhere) in place of the ATT APN info and you should be good to go, presuming your phone is SIM-unlocked. Instructions on SIM-unlocking it should be in the ATT i337 forum, if you're not already unlocked. For example, when I got my M919, all I had to do to get it to work on ATT was enter the APN info from ATT, and BOOM I was on the network. I bought a pre-SIM-unlocked phone to avoid having to unlock it myself.
I hope this is at least a little helpful even if it's not all the answers you were hoping for.
Marc

LMG820UM3 on US Mobile (Verizon) - Need Help

Hello,
I will try to keep this short and sweet.
I am on US Mobile using the black sim (verizon towers) and currently have a LG v30 that no longer can make calls due to Verizon shutting down cdma beginning of 2023.
I have my brothers Lg G8 ThinQ phone purchased from US Cellular. It is now rooted and I followed this guide to add LTE support for other carriers:
[GUIDE] [NO ROOT REQUIRED] [EPIC UPDATE] How to add VoLTE support for other carriers to the G8 (and other Qualcomm powered LG devices too!)
This guide will not work if you are running Android 12 :( I'm gonna keep the intro simple, been a longtime user here on XDA, and recently I found that my T-Mobile LG G8 only supported VoLTE and VoWifi on, you guessed it, T-Mobile! So I did some...
forum.xda-developers.com
I used the mbn files provided from the guide and loaded a few of the US carriers. Upon putting in the sim, and trying to change settings to get it to work, I can only get data to work but texting/calling (in/our) does not work at all. When attempting to make a call, the 4G indicator also disapears. I contacted US Mobile thinking it maybe was a APN issue but they stated on their end that the phone is incompatible.
Not sure what else to try. My only hunch is maybe reloading mbn files from a downloaded KDZ but I have no clue if that will work (also to download 5 gigabytes takes a few days for me).
Any help is greatly appreciated.
attached is both the phone info and a snapshot of PDC of it showing VZN got activated on the phone with the sim in it.
EDIT:
For if anyone else comes across this. My solution was to crossflash (using the guide in the LG G8 fourms) the open market KDZ and I went with G820QM30c_00_NAO_US_OP_0103.kdz as I had android 11 already installed and that it was the A11 version download the most from here: https://lg-firmwares.com/lg-lmg820qm-firmwares/
I did have to correct my FTM partition but that crossflashing guide links to some good solutions.
*Note: Only issues that I have seen with the version i flashed is i cant add an APN. The button is just missing so had to install an app to view it, and when receiving gifs, they turn into pictures only. both things I can live without as not volte works on verizon (us mobile).

So, which rom would normally work with that carrier? I'd guess the us open version would work, why not just flash that on the G8? I've no idea what bands us cellular rom supports, but I'd trust the correct rom (for the current carrier) to work rather than following that thread to 'add bands'.
I used that thread once, didn't accomplish what I wanted. Not to say it doesn't work, I didn't try that long. But have flashed numerous roms re diff carriers, that always does what it should re correct bands.

Frankly, I am not sure if my reply will be helpful, and I know nothing about the US Mobile specifically, but just wanted to comment as an owner of a G8 originally from the US Cellular. Feel free to ignore this if it seems irrelevant...
I bought my phone second-hand with an original US Cellular A11 stock ROM. Later cross-flashed it to the Canadian Open when A12 became available. Rooted with Magisk. I am using the phone on the Rogers network in Canada. On both ROMs I have no issues with data, voice and text - everything works, including concurrent voice calls and data usage.
A (possibly) dumb question - have you tried the original US Cellular ROM as is, before diving into the guide to add LTE support for other carriers? Is there a chance that it would just work?
Regarding the previous reply, I couldn't find a US Open ROM available for the 820UM models (only for QM), but you could try Canadian Open, for example. My point is to try and make it work with one of the ROMs as is, without messing with some extra steps that may or may not work.

AsItLies said:
So, which rom would normally work with that carrier? I'd guess the us open version would work, why not just flash that on the G8? I've no idea what bands us cellular rom supports, but I'd trust the correct rom (for the current carrier) to work rather than following that thread to 'add bands'.
I used that thread once, didn't accomplish what I wanted. Not to say it doesn't work, I didn't try that long. But have flashed numerous roms re diff carriers, that always does what it should re correct bands.
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Click to collapse
Yeah, I guess i understood that as being able to add the functionality. But after more research, flashing a different rom is more likely to be the solution, which confuses me about adding profiles if it doesn't truly work?
kt-Froggy said:
Frankly, I am not sure if my reply will be helpful, and I know nothing about the US Mobile specifically, but just wanted to comment as an owner of a G8 originally from the US Cellular. Feel free to ignore this if it seems irrelevant...
I bought my phone second-hand with an original US Cellular A11 stock ROM. Later cross-flashed it to the Canadian Open when A12 became available. Rooted with Magisk. I am using the phone on the Rogers network in Canada. On both ROMs I have no issues with data, voice and text - everything works, including concurrent voice calls and data usage.
A (possibly) dumb question - have you tried the original US Cellular ROM as is, before diving into the guide to add LTE support for other carriers? Is there a chance that it would just work?
Regarding the previous reply, I couldn't find a US Open ROM available for the 820UM models (only for QM), but you could try Canadian Open, for example. My point is to try and make it work with one of the ROMs as is, without messing with some extra steps that may or may not work.
Click to expand...
Click to collapse
So yeah, after more research, looks like flashing either the open market or the verizon specific variant would work. I did try it first without any modifications to the us cellular rom but still not everything worked. I have a Lg v30, but few things that are no longer ideal was the recent CDMA discontinuation from verizon at the start of this year, also had recently dropped it and the screen flashes bright white light in your eyes at random times... so lol, not ideal.
What Im probably going to be trying when I get the time is flashing the open market, and if that dosent work, it seems the verizon specific would.
Thanks both for the inputs!