You should now see a screen that says “Firmware Update” with a progress bar at 0%. Method 2: Using ADB Commands (Phone must be booted) Use this method if your phone is already on and you have USB Debugging enabled.
Connect your phone to the computer and open a command prompt / terminal. How to Open Download Mode on LG V40 ThinQ
On your LG V40, go to Settings > Developer options and enable USB Debugging . You should now see a screen that says
Keep holding Volume Up until you see a screen with a small image or text saying “Download Mode” (or a firmware update screen). go to Settings >