Franke disposal with electronic control does not respond to the wall switch; E4 or four blinking LEDs indicate a control board fault.

Safety first: Turn OFF power at the breaker and verify with a non-contact tester.

• Inspect for moisture: Remove the cover of the Franke control box under the sink. Look for signs of water drips, corrosion, or condensation. If moisture is present, identify and fix any leaks from the sink, faucet, or dishwasher connection before proceeding.
• Check harness connections: Ensure the multi-pin connector from the control board to the disposal motor is fully seated and free of corrosion or burn marks.
• Look for burnt components: Visually inspect the PCB for darkened areas, cracked components, or swollen capacitors. Any such damage usually requires board replacement.
• Dry and reset: If only light moisture is present, gently dry the area with a cloth and allow the box to air dry for several hours. Reassemble and restore power to see if the error clears.
• Replace control board: If E4 persists, replace the Franke control PCB / power module with the correct part number for your model.

Note: Electronic board work should be done by a qualified technician if you are not experienced with appliance electronics.