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 any disassembly. 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: Unplug the unit for 5–10 minutes, then plug back in and check if F1 clears. Sometimes a control glitch can trigger this code.
• Check keypad for stuck keys: With power disconnected, press each button on the control panel several times. Look for keys that feel stuck or do not click. If the keypad is a separate membrane panel, inspect for visible damage or bubbling.
• Inspect ribbon cable: Remove the control panel (usually a few screws behind the top grille or under the panel). Carefully disconnect the keypad ribbon from the control board. Clean the contacts gently with a soft, dry cloth and reseat firmly.
• Test keypad vs. board: If the code appears immediately at power-up, disconnect the keypad ribbon and power the unit briefly (do not run the microwave). If F1 disappears, the keypad is likely shorted and needs replacement. If F1 persists with the keypad disconnected, the electronic control board is likely faulty.
• Replace faulty part: Order the correct Whirlpool membrane keypad or complete control panel assembly using the full model number. If the board is bad, replace the electronic control board (main PCB). Reassemble and test.

When to call a technician: If you are not comfortable removing the control panel or identifying the correct replacement parts, contact a qualified appliance technician.