. The moment the screen turns off, quickly switch to holding until the Download Mode screen appears Exiting Download Mode : To leave this mode, press and hold the Volume Down + Power
If your LG V40 is fully functional and you have USB debugging enabled, you can force a reboot into Download Mode using ADB (Android Debug Bridge). This is useful for developers who are already connected to a PC.
Your phone will immediately reboot into Download Mode. How to Open Download Mode on LG V40 ThinQ
Power off your LG V40 completely.
: Wait for the screen to light up and display "Download Mode" or "Firmware Update." Once you see this, you can let go of the button. Troubleshooting and Exiting Your phone will immediately reboot into Download Mode
: Release the button once you see the "Download Mode" or "Firmware Update" screen appear. Alternative Method: Using ADB Commands
adb reboot download
You should now see a screen that says “Firmware Update” with a progress bar at 0%.