If for some reason you need to return your AT&T Galaxy S2 back to the store for warranty or you just itch to get back to a completely stock phone, you can unroot/unbrick your phone using methods outlined here, which will completely unroot your phone with stock ROM.
Step 1. Plug in your microUSB cable to your AT&T Galaxy S2 to your computer. Then hold down Volume Up, Volume Down, and Power button together.
Step 2. When you see the warning sign, hit the Volume Up button to enter Download Mode.
Step 3. Download unrooting files here and unzip, then run odin3 v1.85.exe.
Download ATTGalaxyS2Unroot.zip
Step 4. Make sure you can see a yellow highlighted COM box. (the number doesn’t matter)
If you don’t see it, you need to install the correct drivers, simply download and install Samsung Kies software. (Download Samsung Kies)
Step 5. Click on “PDA” then choose ATTGalaxyS2Unroot_SGH-i777.tar file in the unzipped folder then hit “Start”. Your unrooting process should begin.
Step 6. Once unrooting has been complete, your phone will reboot.
Step 7. You will see that your AT&T Galaxy S2 has been unrooted to stock 2.3.4 ROM. If your phone gets stuck on boot loop, don’t worry follow Step 8.
Step 8. You will want to do a factory reset your device completely so take the microUSB cable OUT then reboot into stock recovery by holding down Volume Up, Volume Down, and Power button together until you see stock recovery.
Step 9. Once in stock recovery, choose “wipe data/factory reset” and hit Power button.
Step 10. When it’s complete, choose “Reboot system now” and hit Power button to reboot.
Step 11. Your phone should reboot and you will be completely back to stock ROM.
Now, from here you might want to backup your AT&T Galaxy S2′s internal storage if you have any personal files/media there then erase them before you return your phone.
That’s about it, you can unroot your AT&T Galaxy S2 SGH-i777 model any time back to stock Android 2.3.4. You can always upgrade to future version after unrooting using its system update feature.
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Hi there I am from UK and rooted my phone to see if i was able to do it, I was successful by following your guide.
My phone is unbranded so if i wanted to unroot will your AT&T guide work the exact same ?
I have done everything, backed up my stock ROM, put on clockwork recovery but I have done nothing else…I havnt put any other ROMs on yet…
Just wondering if this AT&T guide will affect the unbranded phone i have
or should i just do the same process i used while rooting and click unroot instead of root and then flash the secure kernal back ?
Don’t use AT&T unroot method here for international/UK version, just flash the secure kernel back.
I followed your instructions and successfully rooted my s2, now the back button and search button don’t work anymore, is this expected?
do u have at&t s2? this is only for att version, but there’s a way if you have the original, not a bad mistake at all.
Thanks for your reply, I figured out what was causing it to happen.
I downloaded several kernels and accidentally picked one for the european s2. With yours though these two keys work just like before.
Thanks!
im having the same problem but now cant hear anyone.
Got it up and running. Thank you very much for making this easy. I am a BIG android noob and this was a great tutorial. But I still can’t get the wifi tethering. I got titanium backup but you can’t freeze hotspot manager with the free version. Is there an alternate route ? Once again thank you.
You can erase the app under /system/app I believe using ES File Explorer with root access.
any mac unrooting instructions for att galaxy s2?
Please!!!!!!!!!!!!
Here is what I did on Linux, which should also work on the Mac as well.
1. Download the above update-cm-7.1.0-Galaxys2ATT-signed.zip
2. Unzip the file
3. tar xvf ATTGalaxyS2Unroot_SGH-i777.tar
3.1 In the untarred directory, you should see the following files:
- Odin3.ini
- odin3 v1.85.exe
- zImage
- factoryfs.img
4. Use heimdall to flash the kernel and factory files
heimdall flash –kernel zImage –factoryfs factoryfs.img
This worked perfectly on my SGH-I777 (AT&T).
What do you know about Samsung’s system for tracking how many times a ROM has been flashed, even after returning to stock? Any way to get around that aside from jamming a jumped USB jig into my phone?
Hi ,
First, thank you very much
I followed your instructions and I did unroote my galaxy s2 successfully but there is a problem the baseband version has not change.
Thank you
Hi! Thanks for your hard work.
I am newbie with andriod phone here and want to be able to use it with T-mobile too. I have questions. Can I use your unroot method to unroot my phone.
This is how I rooted it and I have the following problems now.
Rooting & unlock method
1. Root with ordin 1.85 with this file CF-Root-SGS2_XX_OXA_KH3-v4.1-CWM4.tar
3. Unlock with (apps) SGS unlock
Problems
1. When I inserted AT&T sim card back. I can’t hear anything with both incoming and outgoing call (the phone
rings)
2. back button and search button don’t work anymore
need help please. Thanks in advance
Serene
I’m trading this gs2 for the gs2 skyrocket. Can I still use this rom and root for the skyrocket?
I’m trading this gs2 for the gs2 skyrocket. Can I still use this rom and root for the skyrocket?
Hey yoon. Yes after following this procedure, you can exchange this phone for the skyrocket. The yellow triangle goes away
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Hi Max, hoping you can help. Earlier today I downloaded this and it worked great, took me back to stock. I was thinking that I wanted a rooted android version 2.3.5, so I flashed this kernel:
This full Wipe package has: PDA: XXKI3| Modem/phone: XXKI3| CSC: OXAKI3
Download: http://www.multiupload.com/DYINYCRRD6
from: http://forum.xda-developers.com/showthread.php?t=1103399&page=259
… unfortunately it changed the way the buttons work (back button no longer worked, had to keep hitting home to go back) and I didn’t like it (I didn’t realise that this was not for the AT&T version) … anyway, I tried to go back to stock AT&T version using your kernel in this post, figured I’d stick with 2.3.4 and then use your root version to root and put CWM back , had to use my jig to get into download mode as the up/down/on buttons now just re-boot the phone. I managed to get the stock version on there, the back button now works, but the up/down/on buttons still don’t work properly, they still re-boot the phone instead of putting it into download mode or CWM … any chance you have a fix for this? … also, I keep getting forced shutdown notices for google and sync … would love to just get back to stock and just have your root solution … please help. thanks.
update: since I couldn’t get into CWM or factory menus (no matter whether the phone is off, on or plugged into usb, up/down/on-off always re-boots the phone), I found a ‘factory reset’ option under privacy settings, tried that and it seems to have fixed the forced shutdown notices … just need help please to get the combo of hard buttons fixed back to AT&T/SGH-I777 factory settings (soft buttons all work ok, i.e. back button has returned, after flashing your stock rom above) … so that they take me to CWM (from phone on), factory menus (from phone off) or download mode (with usb plugged in and phone on) as they did before I messed up downloading the wrong version of 2.3.5. thanks.
… it gets worse … another problem, phone rings, dials and connects but I can’t hear anyone and they can’t hear me … guess I really did a number on it.
I am having the same problem. It does not matter what rom I install, the phone has no sound. I cannot hear nor can the caller or callee
Did you find a solution to this problem. I’m having the same problem
I wish to simply get my kernel back to factory but not delete my existing programs/settings. Can I apply ATTGalaxyS2Unroot_SGH-i777.tar and simply not erase all of the files? Basically skipping the second step above to erase all of the files?
Worked as described
Please make an unroot for mac!!!!!!!!!!!!!!!!!!
Hello awesome guy. I rooted my phone yesterday using your instructions on galaxys2root.com. Everything went perfectly. I did a backup and started installing a few roms, including the litening one and had a couple issues with the capacitive touch buttons so I switched back to the stock rooted rom that you included.
Now though, no one hears me on calls and I can’t hear anyone either. BTW my phone is the AT&T i777. Help?? The mic and speaker work though with skype and the cam app.
Did you find a solution for this
Hey man, any chance of Mac directions for the unrooting? You mentioned that you’d have them up in the video but I don’t see them here in the article. Thank you!!
I have the ATT galaxy s2 rooted the way you showed and i want to unroot.
Well my phone wont recognize any usb cables i put in it.
so even when i charge it it wont recognize it, but if i restart my phone with it plugged in itll charge.
not the same with it plugged into the computer.
also i cant find the unroot files anywhere(maybe im not looking right or im passing them up?)
Hey where is the unrooting files? Can someone link me ?
I have samsung Galaxy S2, att version SGH-1777. I rooted this phone no problems. when trying to un-root after downloading unroot file, odin works meaning the box comes up with yellow box, I chek the PDA box and click on PDA but when the the box with the file to click on prompts up, it’s not the un-root file it’s suppose to be. I keep getting the GalaxyS2 AT&TRootZedomax file coming up so I’m stuck. can’t un-root back to factory……If anyone can help I would appreciate it. thx
hi…i did the unroot then did the factory reset. when all was said and done when i made or received calls i couldn’t hear anything nor could the other person hear me…the only thing i seen that may be wrong is the baseband which is I9100XXKH3…from your video it looks like it is suppose to be I777UCKH7…i have a at&t galaxy s2….what should i do…thanks for any help
hi…i unrooted then did a factory reset but now phone rings, dials and connects but I can’t hear anyone and they can’t hear me…the baseband is I9100XXKH3 but in your video it is I777UCKH7…what should i do…thanks for any help you can give…not sure my other post made it…
Did you find a solution for this. I’m having the same problem
Does this work for Non-Rooted Phone? I updated OTA from 2.3.4 to 2.3.6 and want to go back to 2.3.4. Will the above steps solve my problem?
I also did the OTA update from 2.3.4 to 2.3.6 on my Samsung Galaxy S II.
I used this method to take it back to 2.3.4 and everything is great now.
I tried this I was successful in getting back to 2.3.4 from 2.3.6 but my wi-fi turns off automatically. Please help!
Mine too! I feel like a slayed a unicorn…
same here. turn on wi-fi and it turns back off after 20 seconds.
If you want to return to 2.3.4 this is the best way to do it:
http://forum.xda-developers.com/showthread.php?t=1313659
Note that if you updated your phone by downloading the update over-the-air, your bootloader did not get changed. So don’t touch the bootloader that’s on your phone.
I updated and than followed these steps to go back to 2.3.4 and everything seems to be working fine for me so far =)
To Admin,
I too have updated my “STOCK & NOT ROOTED At&t Samsung Galaxy S2 to 2.3.6 OTA last week and wanted to go back to 2.3.4, however I see that few people here are having trouble after doing so like wifi automatically turns off, caller can’t hear etc. and see no posted solutions to it.
Do you by any chance have any suggestions how to fix these problems for people that are already having trouble and for us that wanted to to the above steps to go back on 2.3.4?
Very much appreciate your help.
To Admin,
Please disregard the earlier message posted above, I’ve decided to just follow your instructions and now my phone is back to 2.3.4 stock.
There was only one hiccup after the rolling back to 2.3.4 where I encountered wifi kept on turning off by itself which I thought you might have accidentally left out to mention on your video that wifi will be messed up after the procedure and that only doing a factory reset will fix the wifi issue.
Nonetheless, I am glad that ran into this website and able to get back on 2.3.4 stock to get rid that horrible battery draining issue on 2.3.6 stock.
You Rock!!!!
Thanks.
Thanks for your awesome guides, Max!
You’ve really make it easy for me to get everything out of my phone. Now that I’ve been messing with different Rom and I know how I want to set my phone, I’d like to start from scratch. I unrooted and went back to stock Rom but also want to delete all my files. Do I just completely delete everything in the /sdcard folder or does that contain some system files that should not be deleted? All i want to keep is my titanium backups. I want to delete EVERYTHING else.
before I got to this site, and reading all this good information, I rooted mi Galaxy S2, with a kernel that I found online, which was not the same it had when it was unrooted. is there any way I can look up the original kernel, so I can do it the right way? Thanks for your help!
hi,i root my phone galaxy s2 sgh i777 with you guys its all perfect but when i put the phone to charge OFF he turned by himself in about 5 minutes . why it happen that? and i question my self if I wipe the phone ? i loose my root? or my sim unlock? i unlock the sim with galaxy_s unlock app from the store PLEASE HELP ME
hi,i root my phone galaxy s2 sgh i777 with you guys its all perfect but when i put the phone to charge OFF he turned ON by himself in about 5 minutes . why it happen that? and i question my self if I wipe the phone ? i loose my root? or my sim unlock? i unlock the sim with galaxy_s unlock app from the store PLEASE HELP ME
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Just wanted to say thanks. Keep up the awesome work.
If need be, I will be using this guide to set my refurbed ATT Galaxy s2 i777 from 2.3.6 to 2.3.4 when it arrives new to me in the box. Thanks for all that you smart guys do for us newbies.
the ‘download files here’ link is no longer a link…. is there any other place i can get the ATTGalaxyS2Unroot_SGH-i777.tar file?
did you find one?
I got my Galaxy s2 i777 (2.3.6) a few days ago and i rooted it and my wifi stopped working so i unrooted using this and it put me on 2.3.4 and my wifi still is not working? How can I get my wifi to work again? Please reply soon so I dont go over my Data limit!!!
After using this unroot guide, the MODEM file is screwed up on my phone. Anywhere I could get a new MODEM?
I am trying to download the unroot file from the link, and when i try to extract it tells me the compressed zip folder is invalid and I cannot access the ATTGalaxyS2Unroot_SGH-i777.tar file. Is there another link?
Awesome guides, one problem tho, it takes me about 1hr 10min to download this file. I’m runnign about 82kb/sec. Never experienced speeds like this before. Usually anywhere from 1mb to 5mb/sec.
Used this to move from 2.3.6 to 2.3.4…everything works except wifi! it cannot detect any network and turns off the wifi…any pointers on how to fix this? thanks!
So I want to try this out but I hate how there are always conflicting comments. My phone is not rooted, I just updated to 2.3.6 OTA and regret it because of the really annoying blue over scroll glow. It seems above some people say the followed your instructions and everything is peachy, where as some say there wifi doesn’t work anymore. Can those of you who said it doesn’t work anymore follow the instructions to the T?
I’ve had this running for over 20mins now on a fresh installed system windows 7 ultimate 64bit … drivers are properly installed as ODIN recognizes it perfectly and i was able to attach usb storage before attempting this.. This is what i get from ODIN
Added!!
Odin v.3 engine (ID:5)..
File analysis..
SetupConnection..
Initialzation..
Get PIT for mapping..
Firmware update start..
factoryfs.img
there has been no change in odin or on my phone for 25mins HELPPPP
Hi there, I tried to root my I-777 with a file meant to another model, now it got stuck on boot loop. I tried to follow the steps here, but the buttons aren’t responding, When I hit power to make a data/factory reset it doesn’t do a thing, I’m getting a bit scared here, please help me get my phone back.
how can i unroot my i9100… i rooted using ur new method..
I just unrooted my phone because i couldn’t receive and make a phone call and even listen to my voicemail thinking it was caused by rooting it. Whats wrong with my phone? how can i get it back to normal?
can anyone help me
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I recently unrooted my at&t galaxy s2 and tried to update from 2.3.4. It will download but not install. It does not go past 34% preparing before it says update failed. Any ideas?
Thanks for all you do.
I have a question, the counter from samsung again at zero
gr arnold
I have a question, the counter from samsung again at zero
and can updat the original update`s with kies
gr arnold
im having the wifi problems i flashed back to stock and wifi still wont work
This article was a lifesaver. I completely panicked when it entered the boot loop, but you had that covered! Thanks so much!
I followed your steps and got back to 2.3.4 but my baseband is i77uclc2.. the build number is uckh7.. i cannot ota update to 2.3.6 and wondering is the different baseband is the reason? can you please email me back with help! thx
Hi,
Thank you so much for your brilliant tutorials . I have a few questions though.
I rooted my AT&T galaxy s2 using your one click method and was able to do so successfully.Does this process changes the boot loaders and risks to brisk. I got this mobile sealed packed and factory unlocked now if I unroot the phone using method in your tutorial and use the the unroot file mentioned in the post ,will my phone remain unlocked?
Thanks
I tried to unroot the cell, it gave error and said ” FAIL ”
then i had restarted the phone , when it was in download mode….. now it says
” firmware upgrade encountered an issue. Please select recovery mode on kies and try again ”
please help phone is not starting and kies is not helping me out !!!!!
Thanks friend..
It was really simple.. took me some time to work my way, as I was doing something like this for the first time with my phone.
Just one question, is it possible for you to post Android 2.3.6 Stoke for AT&T.. or a way to select it as PDA with ODIN…?
Anyways… It was working perfectly for me!!!!!
http://forum.xda-developers.com/showthread.php?t=1342348
it helped me out
love this site 
After unrooting. Is there any reason why the OTA Over the air updates doesn’t find any updates? Android 2.3.4 is stock and I know for a fact there is an update that brings it to 2.3.6.Would Custom ROM Count have anything to do with this not working, or is AT&T just selective on when they allow the updates to be pushed. I just ordered a jig to be safe. Any help would be appreciated.
Same here bro. I unrooted but now I can’t update through OTA
Same here, did you find any solutions? and also when I did unroot my SGS2 using the instructions above, my phone keeps on rebooting every 30 mins or so.
I’m experiencing similar problems as well. After unrooting my phone, I’m stuck on 2.3.4. My phone does detect the 2.3.6. update and will download the update. However when it reboots it keeps saying installation interrupted. Any ideas as to why I can’t update my phone? and if future updates such as the official ICS update from at&t comes out, will I also not be able to install that as well?
I am having the same issue, and my network data connection keeps dropping as well and I have to reboot the phone to get it back.
if i done this will it unviod my warranty?
if i done this will it unviod my warranty??
Thank You!! It saved the day!! Greetings from Costa Rica!!
i have 4.0.3 on my at&t device
if i do this method will i be able to get back on 2.3.4
plz plz help me
plz