This happened to me after I took an OTA update from AT&T. It no longer booted and wouldn't show up in Windows or Linux. I ended up sending it to LG and they repaired it and sent back work u by again..
Sent from my LG-D800 using Tapatalk
HTC ONE M7 - Bootloder Unlocked / SIM Unlocked / S-OFF / SuperCID / Rooted FOR SALE
Nexus 5 - Bootloader Unlocked / Rooted
Samsung Galaxy Note 10.1
LG G3 Has arrived!!!
<-- Current Daily Driver
LG G2 D800 running CloudyPro2 + Dorimanx 6.2 Kernel
Please Hit the THANKS Button if I have helped..