Display shows E5 and the unit will not start a cooking cycle.

Safety first: Unplug the unit before any internal inspection.

• Step 1 – Verify outlet voltage: If you have a multimeter, measure the outlet voltage; it should be close to the rated voltage (e.g., ~120 V in North America). Low readings indicate a household wiring issue—contact an electrician.
• Step 2 – Reduce circuit load: Move other high-wattage appliances (kettle, toaster, microwave) to a different circuit. Reset the breaker if it has tripped.
• Step 3 – Plug directly into wall: Do not use extension cords or power strips. Plug the Cosori air fryer directly into the wall outlet.
• Step 4 – Inspect internal connections (advanced): With the unit unplugged, remove the cover to access the AC input and main control PCB. Check that the line and neutral wires are firmly attached to the terminal block and board. Tighten loose screws if present.
• Step 5 – Replace main control PCB: If the outlet voltage is normal and connections are secure, but E5 persists, the internal low-voltage power supply on the main control PCB may be failing. Replace the main control PCB.
• Do not bypass safety: Never attempt to bypass fuses or safety components to clear E5.