Microwave beeps and will not start; F1 appears on the display shortly after pressing START.

Safety first: Unplug the microwave from the wall outlet before removing any panels. High-voltage components can retain a charge even when unplugged; do not touch the capacitor or magnetron area.

• Power reset: Unplug the microwave for 5–10 minutes, then plug it back in and test. Sometimes a control board glitch can trigger F1.
• Check keypad response: Try pressing multiple buttons. If some keys are unresponsive or multiple functions trigger at once, the membrane keypad is likely shorted.
• Inspect ribbon cable: Remove the control panel (usually a few screws behind the top grille). Carefully disconnect and reseat the flat ribbon cable from the keypad to the control board. Look for corrosion, burns, or cracks.
• Clean contacts: If the ribbon contacts are slightly oxidized, gently clean with isopropyl alcohol and a lint-free cloth, then reconnect firmly.
• Replace faulty part: If F1 persists, replace the membrane keypad/control panel assembly. If a new keypad does not resolve the issue, the main control board is likely defective and should be replaced.
• When to call a technician: If you are not comfortable removing the control panel or identifying the correct replacement part, contact a qualified appliance technician.