Beurer humidifier shows an 'F' or flashing fault symbol and stops misting.

Safety: Disconnect from mains before any disassembly.

Steps:

• Full reset: Unplug the unit for at least 15 minutes. Press and hold the power button (if accessible) for 10 seconds while unplugged to discharge capacitors, then reconnect.
• Check for moisture: Inspect the control panel and base for signs of water ingress. Dry the unit in a warm, dry room for 24 hours and retry.
• Visual PCB inspection: Remove the housing and examine the main board for burnt components, bulging capacitors, or corrosion.
• Check connectors: Reseat all harness connectors (fan, transducer, sensors, heater) to ensure good contact.

If the fault indication remains and no obvious external cause is found, the main PCB likely needs replacement. This should be performed by an authorized Beurer service center to ensure safety and compatibility.