Microwave beeps and displays F1, often immediately at power-up or when trying to start a cook cycle.

Safety First: Unplug the microwave or switch off the dedicated circuit breaker before removing any panels. High-voltage components inside a microwave can retain a dangerous charge even when unplugged. Do not touch the high-voltage capacitor, magnetron, or transformer.

• Power reset: Disconnect power for 5–10 minutes, then restore power and check if F1 clears. If it returns immediately, continue.
• Inspect keypad ribbon: Remove the control panel (usually by taking off the top grille and one or two mounting screws). Carefully pull out and reseat the flat ribbon cable from the membrane keypad to the control board. Ensure it is fully seated and not corroded.
• Check for moisture/grease: Look for signs of moisture, steam damage, or grease on the keypad and control area. Gently clean the surface with a slightly damp cloth (no chemicals on the ribbon or board) and let it dry completely.
• Test keypad: If the error appears without pressing any keys, the keypad is likely shorted. If available, use the unit’s built-in keypad test (service mode) or disconnect the keypad ribbon and power up briefly: if F1 changes to a different code or clears, the keypad is defective.
• Replace parts as needed: If reseating the ribbon does not help, replace the membrane keypad (or entire control panel assembly). If a new keypad does not resolve the issue, replace the electronic control board.