[Samsung Galaxy S7 Edge Questions and Answers] lemonloaf:
Owner of a flat S7 here (Canadian version: SM-G930W8 with Rogers, stock firmware: G930W8VLU2API1 ). I just encountered the problem. Device has been in my possession for <5 days; actual first use is today.

I tried to flash a root bootloader from one of the famous thread around here, specifically this one.. There is also this one, but they seem to be using the exact same files. This is not my first experience flashing custom or stock ROMs (previous phone is Galaxy S4).

Here are pictures of the screen:

Initial bricking (same message as of now). Obtained through any attempt at normal booting.

http://i.imgur.com/pEfdXfL.jpg

Download mode is accessible (and device will be recognized in Odin). This was discovered accidentally as I went through the initial shock of understanding what had happened. I kept holding Volume Down + Power + Home button at the same time. This is correlated with other posters from this thread. Note: When trying to access Download mode, device will always reboot once and display the exception. Keep holding the buttons. It will shortly reboot and enter download mode.

http://i.imgur.com/oAJNL4e.jpg

Closeup of the information visible in download mode.

http://i.imgur.com/k6kkt4U.jpg

Recovery mode is accessible. First, a reboot is necessary by holding Volume down + Home + Power, and immeditaly when seeing the screen going black, switching to hold Volume UP + Home + Power. The screen will first show an exclamation mark symbol with an Android, then proceed with the following menu (the standard recovery mode).

http://i.imgur.com/RQN3ese.jpg

A very significant observation is that holding Power and Home together (only those two) for any lenght of time (any) does not result in a forced reboot or shutdown. I always suspected that this was a hard coded feature of every device, as a failsafe. I'm stumped.

I'm all against returning a phone when it's screwed because of a user's error, however considering the current thread and my background in electrical engineering, this sounds plausibly like a hardware failure. As per nitrous²'s suggestion, I would like to contribute my manufacturing date so we could highlight a bad production however it's still soft-bricked at this point.

My action items are for now:

- Use a non modified original firmware, and entirely flash it. (See Update 1 just below)

- Take the item back to the store (see my previous sentence about returns).

Update 1

I have succesfully flashed with Odin the original firmware G930W8VLU2API1, as per the unrooting instructions of the first rooting thread (see first link of this post). The device is now back to a factory reset and boots normally.

Odin interface with files used:

http://i.imgur.com/hBL9e7N.png

After the flashing, on the initial start: http://i.imgur.com/ekuijMS.jpg and finally: http://i.imgur.com/EzazlNi.jpg

I did not try Smart Switch.

Conclusion

In my case, the bootloader exception error was corrected by reverting to the original firmware. This leads me to believe that the rooting for this model is not yet stable or fully functional. This also suggest that a NAND or hardware failure is not involved - I expect that if the NAND area concerned with the bootloader was damaged, I'd still see problems by now too. I don't really know how to contact anyone in charge of the root loader so meanwhile I'll keep lurking and look for a possible update.

I am so relieved now.

Update 2

As per nitrous²'s suggestion, this one has been built on Sep. 1, 2016.