Root Messed up bad, need help.

[Amishjello77]

Okay so i tried to flash my F6 with a new OS. however, when I was in TWRP, i accidentally wiped my zip and the internal storage, and I have been trying all day to fix it, I couldn't sideload because I couldn't mount in internal storage or /data. But, the last thing I tried, messed me up bad. Now my screen is black and nothing even comes on. This was the last thing I tried: http://forum.xda-developers.com/showthread.php?t=2683787
Specifically this step:
adb shell
killall -19 recovery
make_ext4fs /dev/block/mmcblk0p8
reboot
I typed in the code, and the whole thing froze, let it sit for about 3 hours before taking out the battery. and now I have a black screen.

I am now trying to do some instructions to unbrick my phone, however I need to be in download mode, and I cant even tell if my phone is on. My PC says it is an unrecognized device and has been disabled.

 

[JayzTwoDimes]

Have you tried to restore to factory using the lg mobile upgrade tool? Just plug your phone in to your pc while it's turned off, hold down power + volume up and it should put you in 'download mode'. From there just go to 'options' -> 'upgrade recovery' and it should restore you completely to the original rom.

Edit: If you can't even get in to download mode then I don't know what to say. I've never had that happen to me, nor have I had to ever use adb for this phone.