On your LG V40, go to Settings > Developer options and enable USB Debugging .
While still holding Volume Up , connect your phone to a computer using a USB cable.
Type the following command and press Enter: How to Open Download Mode on LG V40 ThinQ
Keep holding Volume Up until you see a screen with a small image or text saying “Download Mode” (or a firmware update screen).
Download Mode (often called Firmware Update mode) is a low-level state on your LG V40 that allows you to flash stock firmware, unbrick the device, or perform system repairs using LG's official software (like LG Bridge or LGUP). On your LG V40, go to Settings >
Actions performed in Download Mode (such as reflashing firmware) will erase your data. Back up your phone before proceeding. Method 1: Hardware Key Combination (Most Common) This works even if your screen is frozen or the phone is bricked.
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. Download Mode (often called Firmware Update mode) is
Connect your phone to the computer and open a command prompt / terminal.
Install ADB and Fastboot on your computer.