The microwave begins a cycle and then shuts off, resets, or stops heating within seconds. This symptom can have more than one cause, so the full model number and operating behaviour matter.
Common causes
- A door-interlock signal is dropping out
- The internal cooling fan is not moving enough air
- A thermal protector is opening because of overheating
- The inverter, magnetron, power supply, or control board is failing under load
These are diagnostic possibilities, not a parts list. The same symptom can be produced by a mechanical problem, a loose connection, or an electronic fault.
How the problem is diagnosed
A technician observes whether the display loses power or only the heating stops, then checks interlocks, ventilation, fan operation, thermal protection, supply voltage, and the heating circuit. Testing under load helps identify faults that do not appear while the unit is idle.
The findings should be explained before any repair begins. Appliance Repair Pro provides an upfront repair estimate, and no repair proceeds until you approve it.
Information to prepare before the visit
Record the approximate number of seconds before it stops, the selected power level, and whether power returns on its own. A short video can also help when the symptom is intermittent, provided it can be recorded without operating an unsafe appliance.
Repair or replace?
The decision depends on the failed part, model age, parts availability, installation type, and the condition of the cavity, door, and controls. Built-in and over-the-range models may justify repair when the cabinet and door are sound; severe cavity or door damage can change that decision. A diagnosis allows you to compare the repair estimate with replacement and installation costs.
