I see you have bricked your LS980 or G2 from sprint it ok i have as well many times and have not seen a guide on this site so here it is. Just follow steps listed Below .

WARNING USE THIS IF LAST RESORT WIPES DEVICE CLEAN USE MODS LINK TO KEEP YOUR STUFF

Step 1. You will need the LG Flash Tool i have it with the DL file inside just copy it to your "C:" Drive after extracting it
Step 2. Download your choice of software to revert to.
Links
Firmware
Dont forget to extract the TOT file
Cant forget the Drivers scroll untill you find LS980
Step 3. Launch the tool
Step 4. Select Manuel Mode then select the DL Flash file and then select the TOT file you wish to flash where ever you have it
Step 5. Boot to download mode by holding Vol + and then plugging in the device to the computer.
Step 6. Click the yellow arrow when it says ready unplug the device and reconnect it the tool should start

Side Notes Make sure to have device under device manager to have it say COM 41 Credit goes to iowabowtech for reminding me.

ALWAYS BACK EVERYTHING UP

I think thats it msg me on what to edit if i forgot something or Staff tell me if i did anything wrong

 

See i tried that and didnt work couldnt flash the tot file there couldnt find the kdz file mentioned to flash