[XDA Assist] Trulypoor:
Hello everyone,

First of all I would just like to thank everyone and anyone in advance for any help at all they can give me. I would also like to says thanks for this awesome community with all this great information you all share! I am certain there are probably thousands of others who have asked for help with a very similar situation. Through all my research these SM-G870A phones seem to be a bit more problematic than most and less common as well, so I decided to open up a thread in hopes this will help more than just myself someday.

I attempted to root my Samsung galaxy S5 active AT&T (SM-G870A) last night and I have gotten in over my head on this one. I am a novice root android user obviously. I attempted to follow this guide from muniz_ri:

https://xdaforums.com/att-galaxy-s5/general/how-to-root-g870aucu1aoa1-4-4-4-2-7-2015-t3025119

I think his guide is great, but it was the wrong one for me since I didn't already have root.

I didn't take my time and do enough research before attempting this and I know better than to do stupid things like that I really do. My phone has the OTA firmware 6.0.1 on it, so I don't think I should have tried to gain root access in this way unfortunately for me. I completed the first 4 steps and odin successfully completed flashing the G870A_NE4_Stock_Kernel, but now all my phone will do is boot up into android recovery over and over again. I believe this is referred to as boot looping.

I have tried wipe data/factory reset/reboot and I have tried wipe cache partition followed by rebooting with no luck. No matter what I seem to attempt I just get booted right back into android recovery.

I have done alot of reading all over the web, but mostly here at XDA and at this point I am lost about what I should do to recover my phone back to working condition. I would be satisfied just having my phone back with root or no root at this point. I think it is just boot looping from what I understand. I have searched everywhere for an original copy of the 6.0.1 firmware so I could flash it back with Odin, but no luck so far. It was really stupid of me not to make some kind of copy of my firmware and stuff first before trying this. I do have one thing that might help me, but I am not sure. I have a backup of my phone made using Samsung smart switch software on my SD which I copied over to my computer. I am going to continue researching and attempting to fix my phone anyway I can, if anyone would be willing to help me in any sort of way I would greatly appreciate that so much! If there is anymore information you would like me to provide please just ask!

It looks like some others having similar issues on their Samsung galaxy phones were able to resolve them by flashing the correct cf auto root file. I checked for a file on the cf auto root site that might work for my phone, but they don't have (SM-G870A) available. I did however find SM-G870W for 6.0.1 here

Here is the Odin log from the CF Auto Root attempt:

<ID:0/004> Added!!

<OSM> Enter CS for MD5..

<OSM> Check MD5.. Do not unplug the cable..

<OSM> Please wait..

<OSM> CF-Auto-Root-kltecanactive-kltevlactive-smg870w.tar.md5 is valid.

<OSM> Checking MD5 finished Sucessfully..

<OSM> Leave CS..

<ID:0/004> Odin engine v(ID:3.1005)..

<ID:0/004> File analysis..

<ID:0/004> SetupConnection..

<ID:0/004> Initialzation..

<ID:0/004> Get PIT for mapping..

<ID:0/004> Firmware update start..

<ID:0/004> SingleDownload.

<ID:0/004> recovery.img

<ID:0/004> NAND Write Start!!

<ID:0/004> FAIL! (Auth)

<ID:0/004>

<ID:0/004> Complete(Write) operation failed.

<OSM> All threads completed. (succeed 0 / failed 1)

<ID:0/004> Removed!!

Its not super clear, but here is what my phone shows after attempting CF Auto Root (SM-G870W) on my (SM-G870A) phone in download odin mode.

After further researching apparently this CF auto Root (SM-G870W) file wont work for my (SM-G870A) phone, because my build number is different. Here is all the info for the current OTA firmware installed on my phone.

Jan. 12, 2017 •What's new: Android device security updates

•Android version: 6.0.1

•Security patch level (SPL): December 1, 2016

•Baseband version: G870AUCS2DPK3

•Kernel version: 3.4.0-9723602

•Build number: MMB29M.G870AUCS2DPK3

•File size: 27.7MB

•Previous versions required: G870AUCU2DPK2