To all who are using the latest version of the Samsung Galaxy S2 tablet. I purchased this from Best Buy @ $249.99 sale price (not sure how long it lasts there - but Samsung.com is advertising thru 12/25/16). The screen is perfect for use in the sun and fits the Mavic RC perfectly.
Now my device is the T713 version and out-of-box would not connect properly to the RC. After reviewing lots of forum posts here, DJI.COM and elsewhere - it's a conflict with the new Marshmallow Android release 6.0.1 (at least) where the USB service defaults to charging only on startup. I read where you could enable Developer Options on Android and then Turn On USB debugging which allows you to select the USB mode (in this case RDNIS was what is needed - at least that works for me). Unfortunately, the mode will not persist after disconnection and must be reset and the tablet rebooted.
When I first tried this the DJI GO App 4.0 would still not connect. When I enabled the Developer Options|USB debugging I could see the mode was cycling very rapidly from charging to MTP to RDNIS and back again and again. So fast that you couldn't select the DJI GO apps startup box to default to this app on connection. The RC and Mavic would not connect in the app no matter what sequence of bootup.
What I found was the DJI USB type A to micro-usb cable was part of the problem. I used a "known working USB data cable" to connect the RC to the Samsung Galaxy S2 tablet. I used the Developer Options to select the USB mode as RDNIS - and then powered off the tablet (thus leaving it in RDNIS mode for bootup).
I then followed the sequence that Jack quotes above and everything worked - first time. You should realize there is some risk in using this method because if the USB cable is accidentally removed from the micro or Type A connnection the app will not regain connection. You will then be forced to un-cable, force the USB mode to RDNIS mode (as outlined above), power down tablet, reconnect the USB cable and power on tablet [all while your Mavic is hanging up in the air]. The other backup plan would be to have another device ready - like a phone or other tablet - for emergency reasons.
I flew 2 batteries duration flights today - with absolutely no issues - fast performance on the tablet, I also loaded the
www.mobizen.com app from Google Play Store and receorded downlink video from the Mavic to the tablet and ran the screen capture recording feature of mobizen app simultaneously with no hiccups.
Just thought I would put this out there for those that might be struggling with the same issues.
Thanks Jack for outlining the sequence of power-up that worked. Hopefully Google will do something different to allow better control of the USB mode in the future - it's causing all kinds of other issues for people hooking android devices to PCs and other stuff.