yashsingh1/xdaforums huggingface dataset:
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
When I experienced that one missing text msg, I was using Textra as well. When I was using the Samsung default messaging app, I never had any issues.

Try switching back to the Samsung one and see if that fixes it.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] squirrell84:
sprint gave me my msl ...tell them your having a problem activating.. and that you try all there steps tell them that you need to manually activate the device thru ##data# and they will give you the 6 digit code
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Update:

Sluggishness:

So the sluggishness was too much. I've done a factory reset with the U firmware, and this time, I did not restore from a smart switch back up... it seems MUCH better, BUT I still see sluggishness when under heavy network activity. For example, if I try to download a Youtube playlist, unlocking the device becomes slow as well simple things, like pulling down the notification shade. If anyone is on a PG1 device, it would be very helpful if you could see if your device does the same. Maybe I've simply never noticed it before.

***Testing downloading a large youtube playlist on a PG1 ROM yeilds the same results... This is just something I never noticed before.... Not a ROM issue :)

SMS:

I can also now confirm some SMS weirdness. Some of my messages are being send multiple times. This is usually when the device is in a sluggish state. I use hangouts for sprint SMS and GV. Outgoing messages will be stuck in a "sending state" until I get a notification that the message failed to send, though the message did in fact get sent, sometimes more than once.

Going to keep digging on this and see if I can find a solution.. If not, I'll jut flash back to PG1

Other Updates:

First time flasher here. Everything seem to be working. So far I've tested calling, SMS/MMS, Samsung Pay, Camera, but there are some odd quirks that I'm noticing. If anyone else is seeing these, I'd like to know

1. The phone is very sluggish when waking. Meaning if I leave sitting for a while and pick it up. I usually have to wait a 5 to 10 seconds before it responds normally. Im running GoodLock (which ran great on the Sprint ROM) but I've seen several complaints about it potentially being a culprit of sluggishness.

*** factory reset cleared all abnormal sluggish behavior... with the exception of downloading a youtube video playlist

2. I can seem to set a different notification sound for Hangouts. It always defaults to the standard sound eve though it shows the correctly selected sound. I wonder if there could be an issue with using SmartSwitch to restore from a backup.... hmmm.

*** The notification issue was a bug in Hangouts. When changing a notification sound, it should prompt you for the storage permission. The latest Hangouts version does not prompt you on PG9 or PG1. Once I manually added the permission, all was good!

3. I had one issue this morning where my hardware nav buttons, stopped working all together. I had to reset the phone to get them back.

****Have not seen the issue since I ran a reset of PG9

Love the lack of bloat and extra enhancements to some of the features

-The Camera has a new Shape Correction toggle. Going to play with that...

-For Musicians: This ROM supports Google's Pro Audio low latency. I'm now able to set the OpenSL buffer size down to 192 buffers!
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Soooperstar:
I had this happen to me about a month ago after flashing stock firmware that I've used several times before. I gave people my Google Voice number in the meantime, called Sprint, the did a reset, I did a reset on my end, and tried everything that I could think of with no luck. After about a week, it fixed itself and they started working on its own
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] klte:
With the unlocked ROM on a Sprint S7E, do I use the unlocked root method, or do I still use our weird Odin Qualcomm root method?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] LeftyGR:
Neither. 935U is not rootable. Well, it is... But you will have no data. Currently no fix for this.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Anyone know if you flash the U rom over the latest PH7 Build?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] themisterwilson:
One or the other. The don't have any dependency on each other.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Thanks. Wasn't sure how to tell if the bootloader had been upgraded or not when I took the PH7 update. Thinking of flashing the U rom again.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] tulorua3:
Dear experts

Please could someone take a look into this issue i am facing here

My phone was in G935PVPU2APH7. I flashed PEH G395U into it, the process was just fine (result = PAssed) but phone was brick, it promted that:

dm-verity verification failed

need to check drk first

I am finding the answer for the issue. It really made me headache :( , not sure why it is happening

Ps: Sorry if this issue is already posted somewhere in this topic

---------- Post added at 07:57 AM ---------- Previous post was at 07:53 AM ----------

I faced problem when i was doing so. I am asking for someone's help

Hold on and wait
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] LeftyGR:
Were you rooted before? And did you load all 4 files in Odin to flash? (AP, BL, CS, CSC)
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] tulorua3:
Dear LeftyGR, Thank for your reply

Yes I did. The phone was unrooted
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] LeftyGR:
OK. That's all I had for a problem possibly. I personally flashed to PEH then took the update to PG9. But that was because I had PEH on my computer and didn't want to download the whole new rev. I haven't had any issues like you're describing.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Any chance you used the wrong CSC file?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] tulorua3:
Hi, I used exactly the one attached in 1st post
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
But there are two CSC files in the download. has the work HOME in it. If you used that one, that could be causing your issue.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] tulorua3:
Yesss. You are rite!

I flashed with the CSC, it works like a champ

Thank you guys!!!
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Glad that was it! Probably going to flash mine again soon.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Nrod0784:
Does anyone have a faster download available? Seems to be taking forever on all options in the OP.

Also, I've used ODIN before, but what four files is everyone talking about to add in order to flash this? Do I need to unzip the file and use all files? Just a little confused on the whole process for this.

Thanks!
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Nrod0784:
Nevermind I figured it out. Loving the no sprint bloatware.

Also battery life is much better. Nearly 3 hrs screen on time first run and still 47% battery left. Rock on!

Edit: 4g Lte speeds seem improved as well here in Madison WI.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Ugh, Sammy is lagging on the security updates again. My 2-yr old Note 4 (N910C) is already on the Sept update.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Yeah, as much as I like this ROM, I think the carrier's will still get update priority.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] El.Dante565:
I am guessing that there still isn't a good root method for the Unlocked firmware. From what I gather the method used on the sprint firmware works, but there is no service or something like that. Is there any sort of temp method? Where you could have root, do a few things then unroot?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] themisterwilson:
That sounds fantastic! Is there anything like that for any device?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] jw7997:
Running this PG9 SM-G935U ROM on my SM-G935P from Sprint for a while. No issues. I just paid off the lease on my device...Sprint is supposed to automatically DSU since I own it now.

Anybody know if running the SM-G935U software will affect Sprint's unlocking this device? Would I need to be on the SM-G935P ROM for that to work?

Thanks!
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
My unlocked N910C Note 4 received an update with Sept security that also included the new Samsung Cloud. I'm hopeful the 935U will also receive Samsung Cloud.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Try it & let us know.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Samsung Cloud is so much better than the Google backup, especially when it comes to app backups. Cant wait for Samsung Cloud to come to the 935U.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] djconundrum:
New update people pi3
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Whats new in the update?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Looks like the bootloader gets upgraded here so proceed with caution as you might not be able to reverb back to the sprint rom if need be.

https://www.reddit.com/r/GalaxyS7/c...riant_october_update_pi3_now/#bottom-comments
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] wojo797:
Had anyone tried the update? Hotspot still a go?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] DatDude123:
Mine is still working like a charm.

D
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
can you confirm if the bootloader has in fact been updated?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] DatDude123:
Yes.

D
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Thanks

That made a lot of T-Mobile users happy, but now we have to wait for Sprint to update ours if we want to revert back. Right?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] DatDude123:
I honestly do not know my friend.

D
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Was expecting Samsung Cloud. Too bad. Maybe in the next update. Still cant believe the Note 4 got it first.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
That's crazy they haven't added that to this build yet.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] jickdotti1:
we do have access to the cloud just read another post on android central originally by vmmatty use shortcut master look for scloud I did it myself and was able to back up my phone to samung cloud
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Do you a link?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
I found & read his post. The Samsung Backup found in our phones is different from the Samsung Cloud backup which is only found in the Note 4, Note 4 Edge, and Note 7 at the moment. He says the same thing himself.

I'll post pictures of Samsung Cloud from my Note 4 tomorrow to show you the difference.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Here are the pics that show the differences between the old Samsung Backup and the new Samsung Cloud Backup.

On my GS7E:

On my Note 4:
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] klte:
I'm on the PI3 SM-G935U firmware, and now I get an error any time I try to reflash the SM-935P firmware. I can't downgrade to the PG9 SM-G935U firmware either; I get the same error. Anyone else experiencing this problem and/or know of a solution?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
I believe this is due to the upgraded bootloader in PI3. You'll have to wait for the a Sprint firmware to come out with that bootloader to be able to flash back. Are you having issues with PI3 firmware?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] klte:
No data when I root the SM-G935U firmware, and no fix like there is on SM-G935P.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Well unfortunately you're stuck on this build without root until Sprint rolls out an update to the bootloader. Fingers crossed for you, man. I want to hop back on this rom, but wont until I know I can revert if need be
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Euronymous88:
That's the price paid for using the Universal Firmware. It's great because there's no bloatware, I personally have gotten much better battery life and you can modify the APN settings for unlimited Hotspot. I believe it to be so much better than the Sprint firmware. I'll sacrifice root any day for overall better performance and unlimited Hotspot.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] purotijuana:
So guys overall...

SPRINT > TMOBILE Unlocked Firmware?

That way I know if flashing SPRINT or staying as I am.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] sk1tz0:
So I uploaded the latest firmware for SM-G935U onto my SM-G935P. BEFORE I DSU'd through sprint. I got the approval through sprint but since i can't revert back to Sprint Firmware ... Am i stuck?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Have you tried the dsu yet on that firmware? Does it work?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] sk1tz0:
Since its the U firmware i don't see the UICC Unlock option anymore. I've tried reverting back but can't as far as i've tried
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Yeah you can't revert since the u firmware had its bootloader updated. I'd be willing to bet the Sprint bootloader will be updated soon. Maybe there's another work around. If so I'm sure this community could help.

Any ideas anyone?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] junear:
I am contemplating to buy the Sprint device and then install the 935U firmware. I have few questions:

1. Can someone check the network bands of the installed 935U firmware and post here?

2. If I buy a Sprint S7 Edge now, will I be able to install the 935U firmware?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
The 935U ROM supports all the USA LTE lands. If you buy a 935P right now, yes, you can flash the 935U ROM on it.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
1st post has been updated with the download link to the latest PI3 ROM file.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] beattheman777:
Does the hotspot hack using Shortcut Master Lite still work with the new PI3 update?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] crowly100:
It works on mine
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] beattheman777:
I am still on PEH. Is there any real advantage to updating? And if I do, will I have to completely reset up my phone from scratch?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
No real advantage. If you're satisfied with PEH, I say wait until either the 935U gets the new Samsung Cloud or until Nougat arrives.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] deedeebulldog:
After installing the latest posted firmware (P13), my Galaxy apps are missing a lot of apps. Such as I had a Gear section for my Gear fit 2 and it is gone. I have tried to reinstall the app, but it fails. Is this the same with everyone's Galaxy app?

Never mind. Fixed it. I uninstalled the update to the app and everything showed up.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] sk1tz0:
Possible noob question, can i root it from this firmware?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] sosmooth757:
I have the Sprint version on PH7. Can I install the latest unlocked rom and root it being on PH7? I really want the hotspot mod.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] themisterwilson:
Don't think that you can root the unlocked rom and still have everything working.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] gigadigit:
Just wondering. Is there a list of LTE bands available after flashing to 935U?

Will flashing to 935U make the phone the same as the factory unlocked CDMA/GSM Galaxy S7 Edge that's being sold now?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Flashing to the 935U ROM will open up all the LTE bands but it won't DSU your phone. For example, if I stick in an AT&T SIM card into my phone, I cant connect until Sprint DSU's my phone first.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] ryan2202:
what voice mail app are you guys using since there doesnt seem to be a built in voice mail app. I tried google boice but it doesnt seem to work.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] LeftyGR:
I've used Google voice for years. Still working here...
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
I was using Google Voice as well on the U firmware as well. What problem are you having when trying to set it up?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] ryan2202:
Hmmm thanks for the feedback.

I only need it for voice mails so not sure it that matters. Dont need it for messages and whatnot. If there is a better app for that, let me know.

App installs fine, but when I go through setup, Im not sure if its working right. It recognizes its a Sprint phone and tries the integration, then asks you to dial an "*" followed by a long string of numbers. That part doesnt seem to work for me, it gives an error about the star code being invalid. So I tried it with the other option it has (something like letting Google Voice handle it) and it didnt seem to make a difference. Left myself a test voice mail and Google Voice didnt see it.

I guess Ill google how to set it up and see what I can find. If you have any suggestions let me know. Thx
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] MatthewPresley:
Ah ha. That's right. The star codes they prompt you to use are wrong. try *73
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] sunmybun:
B41

Is the 3ca working on this?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Avi8ion:
Want to take the plunge and try out the U firmware.

What steps do I take in doing so besides obviously backing up?

I am coming from PJ2
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Mast3rZero:
Just backup and follow the steps on the first post.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Avi8ion:
Really want to try this but no download link is working for me.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] richardjrdeal:
Why would this be in a thread for SPRINT Samsung Galaxy S7 Edge...SM-935P?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] themisterwilson:
Why would what be? The 935U firmware?

If that's what you're asking, it's because there isn't a Unlocked S7E forum section. Also, it works on the Sprint device.

If I'm understanding you're question right, I hope that answers it
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Like he said, there's no 935U forum section plus this flashing guide is based on my Sprint GS7E phone.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] kalico17:
is there really no way to revert back to the P Rom from the current U version???

I want to get back on SPrints actual rom VS this unlocked. it drops connections for me randomly....
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] LeftyGR:
Keep an eye on this thread for 935P's pj2 firmware

http://xdaforums.com/sprint-s7-edge/how-to/firmware-g935p-pe1-official-sprint-6-0-t3414654

Once it is available, you can switch to that firmware.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] JayDubya09:
Does prior unlocking need to be done before this firmware is Odin'd? Coming from completely stock. I've been holding off on root and decided to jump in and start here for Hotspot and Debloat.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
You don't have to DSU your phone first. Even on the 935U, Sprint will perform the hand-free activation & verify your account. You can still do Sprint stuff like PRL & Profile updates.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Soooperstar:
My thread is updated with the PJ2 download
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] donbudafuko:
Ok so want to know what yhe benefits r to fo to this...i am currently on pf2 an rooted...
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
No Sprint bloatware, smoother, better battery life.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] donbudafuko:
Am i able to back to sprint firmware if need be? Also is there any custome stuff for it?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
No custom stuff for the 935U ROM but you can always flash back to the 935P ROM.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] donbudafuko:
Root or no need for it?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Root is unstable on the 935U, not to mention issues with data. I don't root my Samsung phones anymore for Samsung Pay so no problem for me.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] donbudafuko:
Gotcha ok thanks might give it a shot since it doesnt look like any custome stuff will be coming to sprint anytime soon....
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] donbudafuko:
How do i install is? Im on pf2 rooted...do i need to update the newest then install this or do i need to install the other bootlader or what? Thanks
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Just use Odin to flash the whole ROM.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] donbudafuko:
Ok do i need to be on the new firmware first or can i just do it from this rooted pf2?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Itchiee:
So there is no FM radio on the Sprint version of this firmware? Can anyone confirm for a thanks?

Thanks!
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
You can do it directly from your rooted pf2.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] donbudafuko:
k thanks didnt want to brick my phone or something as its my only phone i have
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] jnadke:
The main benefit is no-root Hotspot.

IIRC the Sprint ROM you cannot edit APN. In this unlocked ROM you can to add DUN.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] markdb77:
After flashing 935U PI3 rom to stock unrooted S7E, does Google Voice Sprint Integration still work?

---------- Post added at 09:57 PM ---------- Previous post was at 09:46 PM ----------

CSC or HOME_CSC ?

Anyone having success with HOME_CSC flash? Some claiming lockup in other threads.

I am going to be flashing 935U PI3 with Odin 3.12 PrinceComsy to stock unrooted PH7.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] optimummind:
Use regular csc when flashing. Doing so will wipe all data so backup your files first via Helium, Samsung backup, Google backup, etc.

And, yes, Google Voice with Sprint integration still works. But you won't have Sprint visual voicemail.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Bigmar75:
Flashed the PI3 over PJ2, running like a champ. Love the empty app drawer..I also like that we can use stock calendar and weather widget with Nova launcher
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] andrewNY:
Correct: the U firmware unfortunately doesn't seem to enable FM radio. This is the same no matter what US carrier you are using.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Duck Quan:
When the U firmware isn't getting a nougat beta fml
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] jralabate:
So it looks like u can't roll back from PI3 to PEH. I tried last night and soft bricked my phone. But all is good I just reflashed PI3.
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] Wacky2bakky:
Anyone else using a Att model s7 edge on Sprint? I have a chance to buy one but I need to make sure I can use it with my sprint account?
[Sprint Samsung Galaxy S7 Edge Guides, News, & Disc] -=puma=-:
Hello.

How to disable the use of the new network when changing sim card of another operator?