Washer-dryer combo will not start any cycle; display shows F01 and beeps.

Safety first: Unplug the combo from the wall outlet or switch off the dedicated breaker before any work. Do not work on live circuits.

Step-by-step checks:

• 1. Power reset: Unplug the unit for 5–10 minutes to discharge the control board. Plug back in and try a rinse/drain cycle. Sometimes a transient fault clears.
• 2. Check outlet and supply: Verify the outlet has 120V (or local spec) using a meter. Confirm the breaker is not partially tripped. Avoid extension cords.
• 3. Inspect main control board (CCU): Remove the top panel (usually 2–3 screws at the back, slide back and lift). Locate the main control board (often in a plastic housing near the rear). Look for burnt spots, melted areas, or a burnt smell.
• 4. Reseat connectors: One at a time, unplug and firmly reconnect the harnesses to the CCU, especially the power input and user interface connectors. Ensure no pins are bent or corroded.
• 5. Test continuity of line filter and harness: If you have a multimeter and skills, verify continuity from power cord to CCU through the line filter. Replace any burnt or open harness.
• 6. Replace CCU if defective: If visual damage is present or F01 persists after reseating and power reset, the main control board is likely failed and must be replaced with the correct Maytag part number for your model.

When to call a pro: If you are not comfortable testing live voltage or replacing a control board, contact a qualified appliance technician.