Microwave runs but does not heat food; turntable and light work, timer counts down normally.

Extreme High-Voltage Danger: The high-voltage section of a microwave can store lethal charge even when unplugged. Do not attempt to discharge the capacitor or test high-voltage components unless you are trained and equipped.

• Basic external checks: Confirm the unit is on a dedicated circuit and not sharing power with heavy loads. Verify the door closes fully and latches properly.
• Listen during operation: Start a 1-minute cook cycle with a cup of water. If you do not hear the typical low hum of the magnetron/transformer, the high-voltage system may not be energizing.
• Internal inspection (visual only): With power disconnected and cabinet removed, look for obvious burn marks on the magnetron, high-voltage transformer, or inverter board.
• Common repair: On many KitchenAid models, a failed magnetron or high-voltage diode is the primary cause of no heat. These parts can be replaced, but due to shock risk, this is best left to a professional.
• When to replace: If the unit is older and multiple high-voltage components are suspect, replacement of the microwave may be more economical than repair.