Microwave shows E3 and does not heat, fan may run briefly then stop.

Safety warning: Unplug the microwave. Do not touch the high-voltage section (transformer, capacitor, diode, magnetron terminals).

• Step 1 – Check ventilation: Ensure the Swan microwave has the required clearance around sides, top, and rear as per the user manual. Remove any obstructions from vents and clean dust from intake and exhaust grills.
• Step 2 – Inspect cooling fan: Remove the outer cabinet. Locate the cooling fan motor near the magnetron. Spin the fan blades by hand; they should move freely. If seized or noisy, the fan motor likely needs replacement.
• Step 3 – Test magnetron thermal cut-out: Find the thermal cut-out mounted on or near the magnetron body. With the unit unplugged, disconnect one wire and test for continuity. Replace if open.
• Step 4 – Check cavity thermal fuse: Locate any additional thermal fuse on the cavity or top panel and test for continuity. Replace if open.
• Step 5 – Reset by replacement: Thermal cut-outs are non-resettable; if tripped, they must be replaced with the exact rating specified for the Swan model.

If the error returns after restoring airflow and replacing faulty cut-outs, the magnetron may be overheating internally and should be evaluated by a qualified technician.