How can I visually inspect the wiring harness connecting the control board and display panel?

First, unplug the washer. Then, locate the control board (usually behind the top or front panel) and the display panel. Carefully examine the wiring harness connecting them for any signs of damage, such as frayed wires, loose connections, or corrosion. Gently tug on each wire to ensure it's securely connected. If you find any damage, repair or replace the harness.