Built-in microwave repair
Over-the-range, built-in and drawer microwaves. Countertop models are usually cheaper to replace, but installed units are worth repairing.
What usually goes wrong
An over-the-range microwave is part of the kitchen: it carries the vent fan and the cooktop light, and replacing one means matching the mounting and the cabinet gap. That makes repair the better choice for most faults.
A microwave that runs but does not heat usually has a failed magnetron, diode or high-voltage capacitor. These parts store a dangerous charge even when the unit is unplugged, so this is one appliance where we ask homeowners not to open the cabinet themselves.
Microwave problems and causes
| Symptom | Likely cause | What the technician does |
|---|---|---|
| Runs but doesn’t heat | Failed magnetron, high-voltage diode or capacitor | Discharge and test the high-voltage parts |
| Sparking inside | Damaged waveguide cover, metal in the cavity, worn paint | Replace the waveguide cover and inspect the cavity |
| Dead display | Blown fuse, failed door switch, control board | Test the fuse, door switches and control |
| Turntable won’t turn | Worn coupler, failed turntable motor | Replace the coupler or motor |
| Vent fan or light out | Fan motor, light socket, control relay | Test the fan motor and its control |
| Buttons don’t respond | Worn membrane keypad | Replace the keypad or control panel |
Try this first
- Check the breaker and try a reset by switching it off for a minute.
- Make sure the door closes fully; a bent latch stops the unit from starting.
- Re-seat the turntable on its coupler.
- Do not run the microwave empty to test it.
Keep it running
- Clean the waveguide cover inside the cavity gently; food buildup there can burn and spark.
- Wash or replace the grease filters under an over-the-range unit every few months.
- Replace the charcoal filter once a year if the vent recirculates instead of venting outside.
Questions
- Do you repair countertop microwaves?
- Usually not. Their repair cost is close to the price of a new unit. Over-the-range and built-in models are a different story.
- Is it safe to use a microwave that sparked once?
- Not until the cavity and the waveguide cover have been checked. Repeated sparking can damage the magnetron.
Microwave still acting up? Book a visit.
Request a repair visit