DIAGNOSIS A completely dead panel points to a power supply issue, not a control board failure (yet). The most common cause is a tripped thermal fuse on the main power line, often due to a power surge or overheating.
FIX Unplug the washer for a full 60 seconds. Plug it back in directly to a wall outlet, not a power strip or GFCI outlet. Listen carefully: you should hear a single, faint relay click from the control area. If there's still no life, check your household circuit breaker. If the breaker is fine, the thermal fuse or main power harness is likely blown.
IF THAT DIDN'T WORK If you heard the relay click but the panel stayed dead, the main control board or its power supply component has failed. This requires board replacement.
HEADS UP LG washers are sensitive to power surges. Using a dedicated outlet and a high-quality surge protector (designed for large appliances) is a preventative must. A GFCI outlet that has tripped will also cause this—reset the GFCI button.