[XDA Assist] DefiantChild:
I've recently started flying quadcopters (DJI Phantom 4 Pro & 3DR Solo). I've been using a Gen 3 iPad to display inflight video and telemetry which also augments the handheld controller. Thing is, iPad brightness is unimpressive in sunlight and there are android apps for the 3DR that are not available to iOS.

So I went to Best Buy and purchased a Samsung Galaxy Tab S2 8.0 with a fairly bright OLED display. I was operating under the deluded impression that the device would USB tether to the Phantom and 3DR controllers as seamlessly as the iPad. It didn't. Specs on the android tablet are as follows:

Device: gts28vewifi

Model: SM-T713 (T713XXU2APK6)

Build: MMB29M

OS: Samsung implementation of Marshmallow 6.0.1

On board memory: 32 GB

External SD memory: 256 GB of U3.

The first issue that I immediately noticed while attempting to connect the Samsung tablet to the Phantom Controller was the small window containing three app icons that repeatedly cycled open & closed as soon as I connected the USB cable from the Phantom controller to the T713 tablet. I started fooling around with setting USB modes (Charging, MTP, PTP, Midi, etc.) thinking that there was a mode incompatibility with the Phantom controller. Nothing seemed to work.

So I put the tablet into Developer Mode, enabled USB Debugging, and flipped the OEM lock off. I fooled a bit with trying to set a compatible mode through the Developer interface without much success. Oddly, when I plugged the iPad into the controller and verified connectivity, then unplugged it and plugged in the android tablet, the android tablet worked fine. (until I unplugged the USB cable. Reattaching the cable after detaching did not reinstate connectivity.)

After fooling around for over 4 hours without any reliable success, I decided that maybe Samsung's USB implementation on this WiFi-Only tablet was less than stellar and I should look at rooting the T713 with a build that implemented USB more effectively and reliably than Samsung's implementation (maybe Nougat?).

I'm an android virgin for all intents and purposes. I've done a fair amount of work on different flavors of Linux, OS X, iOS, and Windows over the years so I assumed that for a first timer, rooting the T713 would not be trivial. I spent several hours reading up on the protocols and tools for rooting, and specifically as it related to the T713. The signal to noise ratio of online information, especially with respect to the 713, appears to be fairly low. But I did find and use Odin (3.07) to install the TWRP 3.0.2-1 tar file according to one online article. I haven't made any further progress beyond that.

After booting into TWRP I noticed that (1) I could tether between the tablet and a Windows 10 machine and eventually get "adb devices" to return a serial number as well as reboot the T713. But I've not been able to get fastboot to connect nor have I been able to upload SuperSU to the tablet. Checking tablet's log, entries complained that the T713 couldn't mount /data and was unable to find the crypto folder. Then I read that /data needed to be formatted (after I had already tried unsuccessfully to wipe it. Okay, my bad. Can't wipe an unmounted device. I get it.) I did, however, manage to get TWRP to format /data.

Thing is, I "assumed" that /data was formatted since the terminal output didn't give any indication of anything in progress. So I think I must have rebooted the T713. The problem now is that the I've had a slowly flashing "Samsung" splash logo throbbing on screen for the past 4 hours; and I think it's looking at me funny.

I've tried to boot it into Recovery Mode and Download Mode without success. TWRP no longer loads. I'm somewhat lost at this point and would appreciate it if someone could point me in the right direction, or link me to some current material on how to either get back into Recovery Mode, or alternatively help me figure out why I am unable to re-flash the tablet.

Thanks