Any help on how to unbrick a D800?

[Pritster5]

So recently, i updated from CM12 (some nightly build) to CM13 following this guide titled: Update LG G2 with Android Marshmallow via CyanogenMod CM13 custom ROM [How to instal] ( I Can't link it because I'm a newbie apparently).

Now, if I try to boot my phone, the LG logo appears on the screen for about a half second then disappears, then the screen is very dully illuminated with absolutely nothing on the screen. As of right now, I can access TWRP (2.8.6.0) and do anything that TWRP allows me too.
In fact, when I installed the CM13.zip it said it installed successfully in the TWRP log window. I can also connect to my PC via MTP and add files to the phone (maybe add .img files that could solve this?). Is there anyway to fix this problem using the capabilities listed above?

EDIT: I also do not know which boot-loader I had. I was coming from android lollipop CM12, so I assumed it was bump.

 

[Subtleone]

So recently, i updated from CM12 (some nightly build) to CM13 following this guide titled: Update LG G2 with Android Marshmallow via CyanogenMod CM13 custom ROM [How to instal] ( I Can't link it because I'm a newbie apparently).

Now, if I try to boot my phone, the LG logo appears on the screen for about a half second then disappears, then the screen is very dully illuminated with absolutely nothing on the screen. As of right now, I can access TWRP (2.8.6.0) and do anything that TWRP allows me too.
In fact, when I installed the CM13.zip it said it installed successfully in the TWRP log window. I can also connect to my PC via MTP and add files to the phone (maybe add .img files that could solve this?). Is there anyway to fix this problem using the capabilities listed above?

EDIT: I also do not know which boot-loader I had. I was coming from android lollipop CM12, so I assumed it was bump.

You might try reflashing CM12, but if all else fails you can go back to stock from Download mode and start fresh.

http://xdaforums.com/showthread.php?t=2663369