Oven display shows E0 and may not respond to key presses or may not start any cooking function.

Safety first: Disconnect power at the breaker before removing the control panel or touching any boards.

Step-by-step checks:

• Power reset: Turn off power for 5–10 minutes, then restore. If E0 reappears immediately, continue.
• Access control area: Remove the control panel to expose the display board and main control board (on some Haier models these are combined).
• Check connectors: Reseat all ribbon cables and multi-pin connectors between the display and main control. Ensure locking tabs are engaged.
• Inspect for damage: Look for burnt components, cracked boards, or corrosion from moisture.
• Check supply voltage: If you have electrical experience, verify that the control board is receiving correct line voltage and that low-voltage supplies (e.g., 5V, 12V) are present. Otherwise, leave this to a technician.

When to replace parts: If reseating connectors does not clear E0, replace the display/user interface board first if separate. If the fault persists, replace the main control board.