Tmobile S8 to Unlocked S8 with AT&T Radios (Carrier Switch) - Samsung Galaxy S8 Questions and Answers

All,
I have an original TMobile, Galaxy S8, G950U. I unlocked it through TMobile and I purchased a Straight Talk BYOP kit from the local Wally-Mart, and put the AT&T SIM into my S8.
I know there are a number of guides out there, to do carrier switching. Trust me I have downloaded GBs worth of carrier firmware and combination firmware, eng boot, what have you. Nothing has worked as far as allowing me to carrier switch.
Here is my issue. The building where I work sucks for Tmobile. It is a hardened building and TMobile's signal does not penetrate. AT&T and Verizon work great. I unlocked my phone through TMobile and was able to flash the unlocked firmware on it. But, in theory, this did not enable all the AT&T radios, because I have an AT&T work phone and it works fine in the same spot, but my S8 cannot send or receive calls, in the exact same spot.
The problem is that I am on Bootloader V3 and I cannot for the life of me find an EngBoot with V3, so I can do a carrier switch and flash the AT&T modem. If someone has been able to do this, or if I just suck at searching, then please let me know, I'll be glad to take the hit.
So if anyone can point me the right direction for BLV3 carrier switches, I would greatly appreciate it!
Thanks all, for looking and trying to help.

Related

att and tmo galaxy s5 identical or different?

I cant find a clear answer if an ATT galaxy s5 will work on tmobile ( phone is unlocked) or will it be missing some features
and also if I install a tmobile stock rom on att phone will it have the wifi calling and all the features of a t mobile phone?
im trying to buy a phone today and cant find any solid info on the internet its a bit confusing
There are lots of existing threads that ask and answer this, so your search missed those (or you didn't search).
Anyway, you can use a TMB phone on ATT without any issues. It doesn't work as well in the reverse as you want to do. The ATT model is missing several frequency bands that the TMB phone has. And ATT, unlike most carriers, also locks the bootloader.
So a (SIM unlocked) 900A phone will work on TMB but will have some gaps in coverage. In a large city with lots of redundant bands that may not be much of a problem. But you will be subject to more congestion, dropped calls and outside of large, urban centers you may even have no coverage i.e. if an area is only served by the bands your phone doesn't have.
And the locked bootloader means that you can't install a custom kernel or recovery. Although you can emulate them with the Safestrap program on an ATT handset. The best way to get the TMB apps, wifi calling, etc is to root and install a custom ROM that is 900T based or 900F based, with the TMB apps added.
.

VoLTE on Unlocked S8 Through Straight Talk

I was wondering if there is a way to get VoLTE working on a factory unlocked S8 that is using a AT&T Straight Talk SIM card. Right now when I make a call, the data goes to 'H'.
Anybody?
I'm not sure if it's possible but have you tried carrier switch your unlocked S8 to AT&T firmware. That's the only way I could get it to work on my unlocked S8 but I do have AT&T though as a carrier
How did you get it to work on att? I am on att as well and it does not appear to be working after carrier switching my unlocked S8 to att branded also wi-fi calling does not work.
ericsting said:
How did you get it to work on att? I am on att as well and it does not appear to be working after carrier switching my unlocked S8 to att branded also wi-fi calling does not work.
Click to expand...
Click to collapse
It worked for me the first time but then the second time I went back to the Oreo beta they went back to AT&T I was only getting H after that when I was calling so I had to borrow my wife's phone IMEI and they provisioned it and it worked again
so how exactly do i go about doing that? I assume this involves calling att or going into a store and giving them the imei from another phone? Does the imei you use have to NOT be already used or can it be in use by 2 phones at the same time? Also so far we have not even told att about this phone we have just moved the sim card so wouldn't they still have the imei of the old phone or do they pull that automatically OTA? If they do pull it automatically then whats preventing it from getting updated again?

What to do with Sprint Samsung Galaxy S7 on the latest firmware

I recently bought used Sprint Samsung Galaxy S7. It turned out the phone is locked to Sprint and is on bootloader v5. I called Sprint but they refused to unlock it even though it is paid in full because I am not the owner of the account that phone is associated with. I bought it from an electronics recycling company, so they cannot help with this. I would like to use it with a gsm carrier, like ATT or T-Mobile. What are my options here? Can the phone be unlocked by third-party? Even if unlocked, can the necessary bands and other settings be made available? Any hacks that trip KNOX are unfortunately not acceptable in my case (it seems putting U firmware with BL5 will trip KNOX).
IMEIGURUS.COM should have a carrier unlock for you. not saying its free.
That is fine but after it is unlocked would I be able to use it with t-mobile or att without issues? I read a lot about LTE frequencies locked, missing menus to set APNs, etc.
It is fine if the answer to my original question is to simply get rid of the phone. I am already considering this, as I naively thought that all it would need is a call to Sprint to unlock it and then flashing the U firmware.
grga1 said:
That is fine but after it is unlocked would I be able to use it with t-mobile or att without issues? I read a lot about LTE frequencies locked, missing menus to set APNs, etc.
It is fine if the answer to my original question is to simply get rid of the phone. I am already considering this, as I naively thought that all it would need is a call to Sprint to unlock it and then flashing the U firmware.
Click to expand...
Click to collapse
There is a thread here about unlocking additional LTE bands.

Wifi calling unlocked ATT S8 ...

So, after reading through several different threads on several sites, the only DEFINITE answer to getting wifi calling on an unlocked S8, even after rooting, flashing, etc. is that you still need to get an IMEI from an ATT branded S8 in order to get the wifi calling, volte, hdaudio, etc. that come with a ATT branded S8??? Has anyone had permanent success flashing the ATT Branded firmware to a unlocked ATT S8 getting wifi calling, etc. to work without having to get a new IMEI? Don't want to have to go through the pains of having to return my unlocked S8, paying the stocking fee (if required) and paying the additional $100 or more for the ATT branded phone. Thank you in advance.
I called AT&T and switched my IMEI to an AT&T S7, but as soon as I connected my unbranded S8 the system automatically switched back to saying I had an unrecognized phone. I don't know what would have happened if I'd used the IMEI from an AT&T S8, because I don't have access to one.

S7 edge SM-935u obsolete ATT/Cricket Feb22?

Ok phone ninjas. I got the notification from cricket today that my SM-935u will not work once 3g is turned off. I found the compatibility list HERE. Note that all the "u" phones after are updateable and should work. And all the att branded phones back to the s4 are compatiable. So, does the hardware exist in the unlocked s7 Edge SM-935u and is there a way to make it work once the 3g network is shutdown? I guess what I'm reading is that post 3g shutdown phones must support VoLTE. The older phones drop to 3g for voice calls. Will texting still work if voice doesn't.
So the questions, can via a software update, booloader unlock, custom rom (such as to the SM-935a firmware), make this phone continue to work? Oh, and if you can provide a step by step guide or link to one that would be great.
Or is this phone just a paperweight in 5 months if on cricket or att?

Resources