[G2 Q&A, Help & Troubleshooting] Mark-7:
Hi all -

Thanks for checking in on my tale of woe. The summary is that I have seemingly nuked my partitions on my LG G2 (Verizon Edition VS980) so that nothing happens when I try to power the device on (literally nothing, no logo, no screen backlight turning on, etc.). In Windows, with some coaxing, the device will appear as a QHSUSB_BULK device (with a yellow exclamation point in Device Manager, and even when I boot into Linux to look at the partitions, they aren't visible.

How I got here:

I was happily running XDABBEB VS980 2.3.0 from http://xdaforums.com/showthread.php?t=2715408 with a few Xposed framework tweaks. Great ROM.

I dirty-flashed XDABBEB's VS982.5 v1.0.0 from http://xdaforums.com/verizon-g2/development/xdabbeb-s-vs982-5-v1-0-0-t2975551 to have a look at the G3 interface. I did a Nandroid backup first, like any good crack flasher

I neglected to read the step in the VS982.5 thread about the fact that this ROM was bumped. I still am not sure what that means.

I played with VS982.5 for a bit, and it didn't really seem like I'd want to use it long term. Also, some of the LG apps didn't seem to work on first try, not sure if that was an additional flash required. (QRemote was what I ran into). Anyway, I thought I'd go back to VS980 2.3.0 for then by just restoring my Nandroid.

Booted into TWRP to restore the Nandroid. It did it's thing.

Upon reboot, the device showed the LG Logo and showed a Security Error in the upper left-hand corner, and sat there briefly, then shut off the screen. (Sorry, I don't remember the precise text, it was in small white letters, several lines' worth of text).

I tried rebooting a couple of different ways, and eventually gave up and followed this guide: http://xdaforums.com/showthread.php?t=2582142

From a Linux Live CD (Specifically an old Hiren's 15.2), I thought I'd followed the instructions correctly. The partitions did show up correctly under /dev/sdk1.../dev/sdk36 or whatever. I did the dd as prescribed with the files.

Then I tried to reboot, and here we are. Apparent hard-brick.

What I've tried since the Linux fiasco.

Rebooting many different ways. (Recovery mode, etc.)

Going back to stock with kdz and tot methods, following this: http://xdaforums.com/showthread.php?t=2432476 . The device is not recognized, probably because the normal USB driver won't load.

Checking to see if it'd show up in adb and fastboot commandline interfaces. No, of course.

Booting back into Linux to try the dd again. No luck. The 30+ partitions don't show up under /dev

Letting it charge, thinking the battery may have died. It has been plugged in long enough that it should be 100%. (I can't tell when the device is on or off any more, because there are literally no indications.). This doesn't seem to have made any difference

Holding the Down button and plugging in the USB port gives the QHSUSB_BULK (Code 28) error in Windows, so at least it's doing something... but not much.

Ideally, of course, I'd like to restore the partitions, get my nandroid written back to the device, and carry on with life. Failing that, I'd like to get the nandroid off so I don't have to spend hours setting up another G2. My mistake for keeping the nandroid on the device - I've never bricked a device this badly, and it's always been recoverable with some googling!

Help! :)