Press & hold---SPIN SPEED & SOIL LEVEL buttons---then press (but not hold) the POWER button.

Wait for the door to *lock* (click sound).

If all of the lights on the CONTROL PANEL are "on"---replace the MAIN BOARD (failing/intermittent power relay).

If all of the lights on the CONTROL PANEL are *not* "on"---replace the DISPLAY BOARD.

Source: flickering display on LG washer WM2016cw