yashsingh1/xdaforums huggingface dataset:
[Galaxy S6 Q&A, Help & Troubleshooting] blazie151:
Any way to get the G920P roms to work on this variant? I've had luck with them with other c-spire/ntelos/r7 phones in the past. I'd like to flash Renegade to it...
[Galaxy S6 Q&A, Help & Troubleshooting] makemesmile:
It works but the phone data Internet won't work can make phone calls and sprints annoying activation keeps posing up and even tried the pit file for cspire no change on that
[Galaxy S6 Q&A, Help & Troubleshooting] TEC602:
Wonder if anyone has got calls working using GSM sim card? I have the cspire G920R7 rooted with LTE data working using AT&T sim.

Won't receive calls (straight to vmail) and when placing calls dialer says CALL ENDED immediatly after dialing.

hmmm.
[Galaxy S6 Q&A, Help & Troubleshooting] Sean89us:
I'm working on this too. So far I've got the same situation as you, Data works but no calls/text.

in a few weeks the person who wants me to unlock this phone for them is switching carriers and plans on buying a new phone to use until I can unlock the S6, so I'll have more time to mess with it then.

There's a few things I want to try, but I can't post links here (XDA rules).

One involves Rooting and using a service code to unlock the bands (google "TeamUSCellular GSM unlock S6")

The other also requires rooting and involves using "galaxy tools" to unlock the bands (not sure if this app works with marshmallow, though) (google "theandroidsoul how to sim unlock sprint galaxy S6")

My hopes are not high for getting this phone to work fully. I've also been trying to get custom ROMs to work, but I can't get the cell radio to work at all on custom ROMs. Even with the stock SM-G920R7 Kernel straight from the latest update .tar
[Galaxy S6 Q&A, Help & Troubleshooting] TEC602:
Thanks for the suggestion, yeah I have tried galaxy tools (GT) to change the phone mode to LTE/GSM auto and tried different CSC values, and accessed the hidden menus through there. The sim unlock in GT asks for a code which I dont know, but the phone doesn't seem to be locked anyway since it doesn't care when I try different sim cards. Weird thing is the GT app doesn't work very well (most hidden menus not working) on the current rom i'm using but worked better on the stock cspire rom. Note, I tried using MSL 000000 in ##3282# data menu and it works but most the settings in there don't seem to be applicable to GSM networks.

Currently I'VE been messing with the build.prop file, also tried the CDMA to GSM flashable zip which edits the build.prop but nothing has gotten better. One time after editing the build.prop the phone would only turn on with a blank screen and vibrate every few seconds, that was SCARY. Also was planning on flashing other radio/modem but having trouble finding many of those files and pulling them from roms seems difficult to get the correct file to flash on odin.
[Galaxy S6 Q&A, Help & Troubleshooting] Sean89us:
I'm not sure you'll even be able to flash other models' modem..? I can't say I've ever tried.

Anyway, getting your hands on the firmware is easy. Just use SamFirm (http://xdaforums.com/galaxy-tab-s/general/tool-samfirm-samsung-firmware-t2988647)

To use it, just input the model number (SM-G920R7/R4/P/V/T/A) and the region code, then select "auto".

Region codes and model numbers:

C-Spire: ACG (SM-G920R7)

US-Cellular: USC (SM-G920R4)

Sprint: SPR (SM-G920P)

Verizon: VZW (Locked out from download, app can't download) (SM-G920V)

T-mobile: TMB (SM-G920T)

ATT: ATT (Locked out from download, app can't download) (SM-G920A)

This app downloads firmwares directly from Samsung servers, so the download is really fast and guaranteed to be perfect/stock.

**the SM-G920R7 is closest related to the SM-G920R4 (US Cellular) & SM-G920P (Sprint). The US Cellular one recently supports GSM Bands natively without any rooting/messing with hidden settings, so that's where i'd start. You may not even need the baseband/modem, just flash the rom? I'm not sure. Good luck dude It'd be awesome if you get it working

*** Also, make sure you have a backup of your EFS before messing with the modem. Apparently if you flash an incompatible modem you can erase/corrupt the EFS partition and lose your IMEI. Hell, make a FULL backup with TWRP, and make sure that backup is copied over to your computer before doing any flashing. You can't be too careful with this.
[Galaxy S6 Q&A, Help & Troubleshooting] TEC602:
Haven't had any luck flashing

stock

firmware or modems from other models using Odin, errors with a security message or something, tried G920A and G920R4. Probably for the best I suppose. Flashing custom roms has not been a problem, even if the don't work properly. Wonder if there is a test mode or way to use logcat to see why calls don't proceed like normal. Never worked on going CDMA to GSM before, I always did CDMA to CDMA in the past.
[Galaxy S6 Q&A, Help & Troubleshooting] phreak311:
I honestly don't remember. I couldn't get calls to work, so I sold that phone.

Data and texting worked by the time I sold it, but no calls was a deal breaker for me.

I have a Moto X Pure (unlocked) now.
[Galaxy S6 Q&A, Help & Troubleshooting] TEC602:
Just a follow up on my Cspire s6 G920R7 attempt to use with AT&T, Sprint S6 root and roms work fine, LTE data worked, phone has a problem making calls on GSM, I am assuming it is trying to use CDMA for calling. I tried all the hidden menu settings to switch to GSM/LTE but to no success getting call working, I ended here using DFS CDMA TOOL/Evolution to try and enable more GSM bands, unfortunately settings will not stick after reboot, may require Samsung 16 digit password?, my MSL/SPC was 000000 so that was accepted in DFS ok. Also based on this thread for other samsung phones, I lost hope in getting it working : http://xdaforums.com/note-4/general/enabling-additional-lte-bands-att-t-t3160864

Here are some pics of the bands listed in DFS, the normal 2G/3G bands are not enabled, I am guessing that is the main problem.

Phone sold, it was fun to get back into the XDA game for a while :)
[Galaxy S6 Q&A, Help & Troubleshooting] Dennis_Hawks:
So, I understood there is no luck to enable (unlock) gsm on this phone even with the galaxy tools (gtools)?
[Galaxy S6 Q&A, Help & Troubleshooting] TEC602:
Not for me, as i mentioned DFS showed normal gsm bands were not enabled and I couldnt enable using the free version of DFS.
[Galaxy S6 Q&A, Help & Troubleshooting] Dennis_Hawks:
I saw on the cspire's website "Before leaving the country, call or text 611 to authorize your phone to work internationally for calling, texting and using data." I wonder what it makes with the phone?
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
Disregard most of this post. I've learned new info now.

I'm not sure if you guys know but you can manually edit the apns with apns.conf. I've never tried this before, but I have a strong feeling a rooted phone could become unlocked for any network by doing this. Someone correct me if I am wrong. Btw, you can root up to 7.0 with the sprint version(sm-g920p) with chainfire autoroot. You guys may also want to experiment with some of the engineering kernels, but avoid the engineering bootloaders. The bootloaders will probably brick your device, only flash boot.imgs. I've tried the sprint eng boot and att eng boot(same chip) with no success.

Also I was able to get into service mode menu on rooted device 7.0 by using a hidden menu app.
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
I hope someone is still following this thread because I have a surprise for you guys... posting here since our phone has no official forum.

I present to you my first Custom ROM based on the official Cspire S6 7.0 ROM.

Features: CSC Removed, Settings app unlocked. APNs settings unlocked, mobile networks unlocked. Adb insecure, Init.d script support.

Installation: First download all files. Install TWRP with Odin and boot to recovery with pwr + volume up + home button. I recommend doing a backup in twrp and putting it somewhere safe before wiping the phone. Wipe EVERYTHING. Install the rom first, then go to file manager in advanced. Navigate to /system/priv-app/setupwizard and delete the folder. You may have to mount /system. Boot the phone and go through setup. Add the correct Cspire APNs and than download the most recent version of google play services for your device form apkmirror and install. You're done! If you want root, follow the Magisk guide.

Tested working:

Calls

4G

Wifi/Bluetooth

GPS

Fingerprint

Audio

Known bugs: The setup app freezes at checking networks because you need to add Cspire apns. The only workaround I know of is to delete /system/priv-app/SetupWizard from recovery. After that, when past setup, install the latest google play services from apkmirror.com. I will patch this soon. Will also likely replace all of the samsung apps with stock google ones. SMS/MMS doesn't work, may be incorrect apns. Feedback appreciated.

Here's the links.

TWRP

https://twrp.me/devices/samsunggalaxys6.html

Magisk Root and Magisk Manger: READ

https://xdaforums.com/apps/magisk/official-magisk-v7-universal-systemless-t3473445

ROM: Blu's G920R7 QD1

https://drive.google.com/file/d/0B_E0jTJbVJ6cYnR1QlNxVWgzRFk/view?usp=sharing

Cspire APNS:

Name: Cspire

APN: internet.cs4glte.com

MMSC: http://pix.cspire.com/servlets/mss

MMS proxy: 66.175.144.91

MMS Port: 80

APN Type: default,supl,mms

Mobile Virtual Network Type: IMSI

[MENTION=2328115]TEC602[/MENTION], I would be very interested in discussing with you what we could do to enable more bands on this phone. I've tried using att sim now that the settings app isn't so restricted, and carrier csc isn't taking priority, but the phone will not connect to att's network at all. I will try a cdma sim soon. I could use help understanding Cspire's network technology. It's seems to be a mixed GSM/CDMA network, CDMA protocols for voice, and GSM for data. Or is LTE a seperate standard that coexists with both?

Credits:

Teamwin

Superr, for his kitchen

TopJohnWu, Magisk
[Galaxy S6 Q&A, Help & Troubleshooting] TEC602:
[MENTION=8284465]bangbusdriver[/MENTION] thats cool u put together a rom for this. I wish i could be more help, this was the first cdma/gsm type phone i tried tweaking, I used to only mess with the sprint phones without sim cards.

For the enabling the other bands the only thing i can think of is maybe a paid version of the DFS software and may need the special samsung password.

thanks
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
I've heard that flashing roms combined with kernels built from source can bypass the protection that qualcomm has built in, but do you know if that hack even works for exynos phones?
[Galaxy S6 Q&A, Help & Troubleshooting] TEC602:
sorry, i got nothing, its beyond my skills, maybe the forum over at idoneeapps could provide some hints.
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
Thanks, Ill look into that. My goal is to unlock this phone , and the custom ROM was part of that. I've heard the modems in these phones all support many more bands than they are configured with. I'll check into the forum you recommended.
[Galaxy S6 Q&A, Help & Troubleshooting] theophile2:
I've got this phone's cousin, the SM-N920R7 (C Spire Note 5) and I've been able to make progress getting it working on AT&T. I was able to use DFS to enable the GSM and WCDMA bands, and now when trying to make a call, it kicks from LTE to HSPA like it's supposed to, but something still isn't quite right as the call doesn't go through and it ends after about 5 seconds. If anyone's still working on this, let me know as I could use a sounding board.
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
I've made more progress with mine as well... I used QPST and QXDM to enable all the bands on my phone and change the default network to any. That, along with the custom rom has gotten my SMS working as well as data briefly. As far as calls, I never even got it to dial out. The call hangs up as soon as it is made with error "incorrect MMI or connection problem". I believe the ROM is stuck on CDMA mode even though I have 4g auto selected in settings and an ATT APN. At least, QPST says it is "Entering CDMA mode"

Perhaps we can help each other out, [MENTION=2748225]theophile2[/MENTION]. I'm pretty new to manual unlocks, but I can get an NV dump from an already unlocked sprint phone, which is similar to many cspire models. I know most sprint phones require an extra step or a few to unlock now. We have a service box at work and it installs an apk during the unlock process... although it hasn't worked for sprint in a while now.

I'm convinced that there is something within the rom besides build.prop that needs attention as well.... but I've tried flashing an engineer rom with a custom kernel and that has not solved the issue... Maybe its an issue with the roaming list?

Also have you turned on GCF in Hidden Menu?
[Galaxy S6 Q&A, Help & Troubleshooting] theophile2:
My understanding is that at least the N920R7 is already unlocked, at least in terms of SIM unlock and carrier unlock. So I've not had to deal with unlock codes or anything like that. I also haven't run into the "incorrect MMI or connection problem" error you mentioned.

Most of what I've done has been using the Phone Info app to access various hidden menus, including ServiceMode, to make tweaks to settings based on various threads and posts online. I also flashed a GSM-compatible ROM for the Sprint variant of the Note 5. I don't believe this is technically necessary, but it does make it easier to select network mode and such from the Settings menu.

I'll try to post more about the experimenting I've done with the various hidden menu settings, but for the moment, I wanted to post a handful of side-by-side screenshots showing signal info between by Note 5 and my Nexus 6P. These were taken within a few minutes of each other from the same location using the same AT&T sim card. In these experiments, I get rock-solid LTE from both devices, but when I try to make a call, the Note 5 drops to HSPA and the call fails, whereas on the Nexus 6P, it drops to HSPA+ and the call succeeds. It appears from some of these screenshots that when trying to make a call, both devices at one point actually connected to the exact same tower, but the Note 5 via HSPA protocol (failure) and the Nexus 6P via HSPA+ (success). I'm not sure why the Note 5 doesn't connect via HSPA+. I'm not sure why the Note 5 doesn't seem to be able to detect the ARFCN/EARFCN of the signal it's connected to.

Anyone have any ideas for what to try next?
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
[MENTION=1912438]Theophile[/MENTION], I believe you are correct about the absence of a network lock on these phones. I'm working on the assumption for now that the MMI error is due to no connection. I need to run some tests with those apps as well, but I have no other sims to work with until I get back to work.

In service mode, my tweaks have been to enable full mode in the frequency lock menus and to turn on GCF. Besides that, I've also edited build.prop item ro.telephony.default_network to 10(GSM/CDMA/AUTO) and 9(GSM/LTE/AUTO).

I've found that flashing stock without the cache.img removes a lot of CSC and allows much more freedom in customization. It changes network select in settings to 4G/AUTO, 3G/AUTO, etc... also unlocks mobile operators menu. This is not the full extent of CSC removal though, I believe there is something else injecting it from system perhaps. I have a hypothesis that the settings for CSpire's network are still being applied at boot. This may be part of the key to unlock. In particular, I am looking at preconfig and autopreconfig.

I'm currently reading up more about how these CDMA and GSM networks work. If you would direct your attention to the screenshot, you can see that the AS and NAS settings in hidden menu comprise part of the GSM network stack. Now, if we want these phones to work with a GSM network, assuming band support, these network layers must be configured properly, no? I've heard that ATT phones require some secret key in storage to use the network.

I'm not sure if those are a GSM/UMTS feature only, but if they are I'm sure the people who configured this handset would have saved themselves some trouble and skipped that part. I've also read that ATT announced back in 2015 that they would be moving over to a VoLTE model...

I did however get perfect working 4G when I tested with a friend's SIM last night. It would seem that the 4G LTE part of the equation is configured correctly for both of us.
[Galaxy S6 Q&A, Help & Troubleshooting] theophile2:
I'm going to try to post screenshots of the various screens and configuration options available through DFS. There were a lot more options than just band selection, most of which I was unfamiliar with. Maybe one or more of those options could be the key.

Another thing I'm wondering about is whether the problem could be in the baseband. From what I understand, the baseband contains the modem firmware and drivers, so while these devices have the same hardware as their GSM counterparts, them radio is still being driven by software designed for a CDMA device, and I suppose it's possible that there could be something in the baseband keeping the radio from working properly with AT&T.

Another thought: I know others have tried flashing basebands from GSM counterpart devices, but this usually results in softbricking that requires reflashing a stock baseband. Apparently this has something to do with different internal partition tables or some such thing. But if these devices truly are all hardware identical, shouldn't it be possible to fully convert the device in every respect to one of its hardware counterparts, partition table and all? Something like a nand dump and 'dd' command? Then it should be as simple as flashing an AT&T stock image and calling it a day.
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
I know for a fact that you have to edit the band preference in NVRAM or the phone won't switch out of CDMA mode. There's a page on XDA that documents the items in NVRAM. I can't post a link, Google XDA NVRAM items and it should be the first link.

I agree with you on the driver's, it's entirely possible that they only support CDMA. Also, I've heard on another forum that updated modem.bins(baseband, whatever) can sometimes have security built in that prevents unlocks... Maybe we should try the first modem from the first firmware released for our devices? More thoughts on that topic, the G920F(for me) is the factory unlocked international variant... It's modem should have support for everything if it's flashable.

On the last point, if it's just a partition table mismatch, a pit file flashed in Odin will fix that as long as you know it will be compatible with your rom and firmware. It's my understanding that the partitions on Android can only be changed that way.

I think it would be quite a challenge to fully convert the device because the bootloader seems to be semi locked. I can flash TWRP, custom kernels, etc with no problem, but when I tried flashing the latest full firmware for g920f, I get errors. The g920p firmware flashed, but wouldn't boot. Ive also tried flashing alternate bootloaders. ATT's bootloader refused to boot anything and has error messages at power on. Surprised my phone wasn't hard bricked tbh. Also the Combination bootloader, but it seems it will only boot combination firmware. TWRP is fine, but it wouldn't load a stock room and kernel.

I forgot to mention in last post, QXDM has a feature that can make the handset call on GSM or CDMA specifically. While I had perfect 4G with ATT SIM it wouldnt call in GSM mode but went through in CDMA... More support for the theory that there is carrier software overwriting our settings with CDMA settings.
[Galaxy S6 Q&A, Help & Troubleshooting] Ricky Rivera:
Can you be more specific on how to install the custom rom?

I really want to try it. I currently have two of this phones sitting on my desk.

Thanks.
[Galaxy S6 Q&A, Help & Troubleshooting] theophile2:
Installing a custom rom is simple. Just flash TWRP recovery, then flash any rom intended for the variant you have. There are instructions all over the forums.
[Galaxy S6 Q&A, Help & Troubleshooting] Ricky Rivera:
I was able to install it. 4G LTE data and text works but no calls. There's no service for calls in 4G in my country, only 3G.

Thanks for the custom ROM!
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
Strange SMS is working for you... it didn't(Lack of CDMA provisioning) when I flashed to rom to my phone but calls worked. I'll be updating that ROM soon, when I find the time, since I've learned more now. There's more carrier bloat that can be removed, and I'd like to do something about the state of the settings app. Also need to include updated Gplay services for easier install and remove setup or activatoin, one or the other.

Can I ask what carrier you are using, [MENTION=8497057]Ricky Rivera[/MENTION]?
[Galaxy S6 Q&A, Help & Troubleshooting] Ricky Rivera:
I'm currently using TIGO Honduras. Calls use 3G service and the phone is stuck in 4G so it won't work. Text messages work fine. I don't know how to install the google play service from apkmirror. I download the file but it wont install.
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
There are multiple versions of the file for different DPI settings/architectures. This is the version I'm running right now https://www.apkmirror.com/apk/googl...s-11-3-02-440-161239932-android-apk-download/

As far as your calls, that's something we are working on now. Have you done anything to try and unlock your phone, or did the 4g and text just work when you inserted your SIM?
[Galaxy S6 Q&A, Help & Troubleshooting] Ricky Rivera:
I installed the google play services from the link you post and its working fine now. Both phones worked after installing the custom ROM. The carrier name was there after inserting the sim card and 4G after setting the APN. One phone has the "Call forwarding - forwarding all voice calls" I don't know why. I can't turn it off. Mobile hotspot works too.
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
Glad its working correctly now. As far the call forwarding goes, I hypothesize that is on the carrier end, not the phone since the other is working. Have you tried the dial codes to turn it off or checked your account for a call forwarding setting?
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
Here is the combination file for the G920R7, as promised. Get it while its hot: https://drive.google.com/file/d/0B_E0jTJbVJ6cQTlyYXJET0h1cTA/view?usp=sharing

[MENTION=1912438]Theophile[/MENTION], after further research, I found a page on the AOSP website that indicates there possibly is indeed an app overwriting our settings with CDMA. There is a default one included with the ROM that provides default settings, CarrierConfig, and may also be another wrote by CSpire that does not necessarily have to be named similarly. I intend to remove both of these and test when I find time. This page can be found at https://source.android.com/devices/tech/config/carrier
[Galaxy S6 Q&A, Help & Troubleshooting] binblogger:
Hello, I also have the same model of s6 the r7 and I would like you to follow this thread I tried to use a rom of sprint s6 and apparently I am from Mexico and I can not have a network

Already I could do it root and others but I **** it of the signal besides that there is not much development you could not carry a rom for this model? I would donate to paypal
[Galaxy S6 Q&A, Help & Troubleshooting] Ricky Rivera:
Hey [MENTION=8284465]bangbusdriver[/MENTION],

Have you had any progress on the custom rom? Thanks!
[Galaxy S6 Q&A, Help & Troubleshooting] bangbusdriver:
I should have time to delete the setup wizard and update applications today.

BTW, [MENTION=8497057]Ricky Rivera[/MENTION], this update will also include an edit to build.prop that may fix your calls. Let me know the result.