E9 displayed; ice maker may not respond to controls or may behave erratically

Safety first: Disconnect power at the breaker before accessing the control compartment. Electronic boards are static-sensitive; use proper ESD precautions.

• Step 1 – Power reset: Turn off power for at least 10 minutes to allow capacitors to discharge. Restore power and check if E9 returns immediately.
• Step 2 – Inspect control board connections: Remove the control panel or top cover to access the main PCB. Reseat all multi-pin connectors, ensuring they are fully engaged and keyed correctly.
• Step 3 – Check for visible damage: Look for burnt components, bulging capacitors, or corrosion on the board. Any such signs typically require board replacement.
• Step 4 – Verify supply voltage: Measure incoming line voltage to the board and any low-voltage outputs (e.g., 5V or 12V DC) per the wiring diagram. Incorrect voltages may indicate a failing board or upstream power issue.
• Step 5 – Replace main control board if necessary: Label and disconnect all harnesses, remove mounting screws, and install the new Viking control board. Reconnect harnesses carefully to the correct headers.

After replacement, restore power and confirm that the E9 code is cleared and all functions (fill, pump, compressor, fan) operate normally.