This is the primary method for entering Download Mode, regardless of whether the phone is on, off, stuck in a boot loop, or frozen on the LG logo.
: Completely turn off your LG V40 ThinQ by holding the Power key for a few seconds. How to Open Download Mode on LG V40 ThinQ
Entering Download Mode itself does not wipe data, but the actions you perform while in that mode (such as flashing a "KDZ" firmware file) wipe your device. Ensure all photos, contacts, and files are backed up to the cloud or a computer. This is the primary method for entering Download