E9
Medisana Internal Communication Error Between Display PCB and Main PCB

Dehumidifier shows E9; unit may shut down unexpectedly.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Loose ribbon cable between display board and main board, Damaged communication harness, Oxidized connectors, Faulty display PCB or main control PCB

How to Fix / Troubleshooting

Safety: Disconnect from mains before opening the control panel.

  • Access control panel: Remove the top or front panel to expose the display PCB and its cable to the main board.
  • Reseat cables: Carefully unplug the ribbon or multi-wire connector between the boards, inspect for bent pins, then plug it back in firmly.
  • Clean contacts: If there is visible oxidation, lightly clean the connector contacts with isopropyl alcohol and allow to dry.
  • Inspect for damage: Look for cracked solder joints on the display PCB connector. If found, re-solder if you are experienced, or replace the display PCB.
  • Board replacement: If E9 persists after cable checks, either the display PCB or main control PCB is defective. Replace the suspect board(s) with Medisana-compatible parts.
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Repair Difficulty

Hard 4/5

Required Part

Display PCB
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