[Galaxy Tab Q&A, Help & Troubleshooting] BrentM94:
So I've had success rooting the SM-T377V thanks to electronhacker post on the forums.

I thought I would give my experience because anyone else doing this will most likely run into the same problems I did. I still have a few problems I am running into. I hope someone can help me out.

electronhacker had said to downgrade to stock firmware LMY47X.T377VVRU1AOL7 (5.1.1) Lollipop, from firmware MMB29K.T377VVRS1BPL1 (6.0.1) Marshmallow using Odin.

I ran into problems finding LMY47X.T377VVRU1AOL7 but I eventually did find it on samsung-firmware.org Thank you moonsh0t!

It did actually work and passed with Odin, however it got stuck in a bootloop. I thought there was nothing that could be done but after looking into the bootloop matter more I figured out how to get out of it and start it up.

1.) Wait for the device to turn off while it's bootlooping.

2.) Then hold down the power button and the volume up buttons to enter recovery mode.

3.) Restore factory defaults. "I think this actually gave me an error but clearing the cache got it to work."

4.) Clear the cache.

5.) Reboot the device.

There you have it now you're out of your bootloop, the device will start up now.

Now that we have downgraded electronhacker had said to run a program called Kingoroot using the Windows application.

I ran Kingoroot and it got stuck at 44% and my screen went black and would not come on or turn off. I am pretty sure you call this a soft brick, but maybe it's called hard brick as there was nothing that could be done.

So this is what I did to Unbrick the tablet:

1.) Hold the power button and the volume down button for 15 to 30 seconds.

2.) The screen should come back on.

3.) Scroll through settings to reboot device normally.

I tried to use Kingoroot again. This time it got stuck at 51% and my screen on the tablet got stuck. Nothing was responding, not the power buttons, the volume buttons, home button, nor the screen. This is because Google Application had showed up on the tablet while I was in the middle of rooting. The Google Application said "Do you want to enable Google Security?".

Again;

1.) Hold the power button and the volume down button for 15 to 30 seconds.

2.) The screen should come back on.

3.) Scroll through settings to reboot device normally.

The device booted normally and I tried Kingoroot again. I wasn't going to give up. This time it worked, 100% Root Successful. I couldn't believe it the SM-T377V was rooted. I checked and verified with Root Checker.

Now this is where I need help!

#1.) The device only stays rooted until you restart it. Then you have to Re-Root it with Kingoroot every time you restart. I found out if you run SuperSu and go into setting you can stop this from happening. I'm not exactly sure what you do yet because I can NOT get into SuperSu. It tried to install the binaries but gets interrupted by Knox. It says disable Knox on SuperSu but this does NOT work. This tablet does NOT have a way to open Knox in order to disable it. So I need to figure out how to delete it that way I can run SuperSu and stop the never ending root process. So if someone could help me figure out how to do that I would very much appreciate it.

So far I've figured out that you can run an application called Titanium Backup to freeze the Knox files and then remove them followed by a Re-Boot to get rid of Knox. I looked further into my SuperSu problems and found out that you can manually download a SuperSu.apk file that should bypass Knox and actually disable it.

Here is my new problem, installed Titanium Backup from Google Play Store only to find out that I can't freeze the Knox settings unless I pay the $5.99 for Titanium Backup Pro. So I removed Titanium Backup and downloaded Titanium Backup Pro.apk which I found for free on the internet. I can NOT install it though, because I have a new error that says "APP not installed".

This happens with the SuperSu.apk that I found on the internet too. I've tried a lot of things but can't get them to install. Google Play Store gives me error (-504) I've tried clearing cache and data for Google Play Store and Google Play Services but no luck. I even tried downloading APK Installer but it doesn't even work. Please help I don't know what to do.

02-09-2017

<UPDATE>

I'm at a loss, so I decided to do a factory reset from settings and that did not get the applications to install. So then I tried to clear the cache but again no suck luck. Then I decided to enter recovery mode and factory reset, but then got stuck on "Your tablet is getting ready for you". or something along the lines of that and wouldn't get past that on start up. (This is because I disabled setup with another application, and is my fault.) Not being able to get past that I realized I had no choice but to Re-Flash the System Update LMY47X.T377VVRU1AOL7 (5.1.1) Lollipop with Odin and that was successful, thank God. Now I have to Re-Root and before installing the wrong applications, which are Google Play Store SuperSu and Titanium Backup. Reason being that once you install these once and uninstall them you can't install them again without getting error (-504) in Google Play Store or even outside the Google Play Store such as manually downloaded .APK files or you will get the error "APP not installed".

Here is my idea, and I haven't done it yet. Re-Flash, Re-Root, Install for the FIRST time the right SuperSu.apk and Titanium Backup Pro.apk in order to disable Knox and stop the never ending Re-Root every time the tablet it restarted.

02-10-2017

<UPDATE>

I have been running Kingoroot with my PC using USB. This gives me temporary Root access until Re-Boot. So I installed Kingoroot.apk and tried using to mobile application but this one works, but I get stuck in bootloop on restart of tablet. Then have to Re-Flash with Odin to get out of bootloop. I'm not having any luck.

#2.) Even with my temporary root I can not seem to install Xposed because of SDK 22 not supported. I was wondering if anyone knows a way to get it to work on SDK 22 so I can run IMEI Changer. Unless there is another way to change the IMEI without Xposed.

Thank you to electronhacker for your post I found on this forum which has made me a lot of progress, and thank you moonsh0t for your help redirecting me to find that firmware. :good: