So, we have all the necessary files. Lets save our LG G3 and don't pay for anything. (I've seen that "androidbrick.com" asks you money for a password of a zip file. Don't trust them.)
2) Unplug your phone from PC and remove the battery.
3) Open the BoardDiag app.
4) Open your computers "Device Manager" (right click to your PC --> Properties --> Device manager --> Ports)
5) Insert the battery and press volume up, then connect your phone to your PC while pressing volume up.
6) On the device manager, find the port number like shown below. (Min e was port 40)
7) On the BoardDiag app (where you have placed it in C:\BoardDiag_for_LGG3) make your selection as shown in the picture.
8) Important part! First select "aboot" from the dropdown menu next to "RESTORE BOOT IMG" (selected)
and Follow the order and do the same steps until your phone goes to "FIRMWARE UPDATE" (aka "DOWNLOAD MODE".)
9) Congratulations! You've just saved your phone. And less important stuff. Lets put our original KDZ rom to LG G3. Open LG Flash Tool and follow the steps below.
Press the "START" on the next page. And wait until your phone come to life ;)
LG G3 Boot Security Bug Fix
4/ 5Oleh okalbinsesi