A microwave that runs through a cycle but doesn't heat is one of the most common service calls we receive. The magnetron — the component that generates the microwave energy — is the most frequent culprit when heating fails completely. It's a high-voltage component that wears out over time and cannot be safely tested or replaced without proper training and discharge procedures.

Other causes include a failed high-voltage diode (which converts power for the magnetron), a faulty high-voltage capacitor, or a thermal cutout that has tripped due to overheating. Each of these requires hands-on diagnosis with specialized equipment. Schedule a heating diagnosis →

A microwave with no power at all — no display, no light, no response — is almost always caused by a blown internal fuse. Microwaves have one or more ceramic fuses that protect the circuitry; they blow when the unit is overloaded or when a door switch fails and causes an arc. The fuse itself is inexpensive, but accessing it safely requires discharging the capacitor first.

Before calling, check your circuit breaker and confirm the outlet is working (plug in another device). If the outlet is live and the microwave is still dead, a blown fuse or a failed control board is the likely cause. Book a no-power diagnosis →

Microwave door switches are one of the most frequently replaced microwave parts. Most microwaves have two or three door interlock switches that must all signal "closed" before the unit will operate — if any one fails, the microwave won't start at all. A broken door latch hook (the plastic tab that clicks into the latch assembly) is also extremely common and causes the door to feel loose or fail to stay shut.

Door switch failures are important to repair promptly — a microwave with a faulty door switch can arc internally and blow the main fuse. We carry door switch assemblies and latch components for all major brands. Schedule a door repair →

The turntable motor sits underneath the microwave cavity floor and rotates the glass tray for even heating. When it fails, food heats unevenly — hot spots and cold centers. Before assuming the motor is failed, check that the glass tray and the ring guide (the plastic support ring that sits under the tray) are properly seated and not cracked or jammed. A misaligned or broken support ring is a very common cause of turntable problems.

If the tray and guide are fine, the turntable motor has failed and needs replacement — a straightforward repair. We stock turntable motors for all major brands. Book a service visit →

Sparking inside a microwave is alarming but usually has a straightforward cause. The most common culprit is a damaged or burned waveguide cover — the flat panel on the interior ceiling or side wall that protects the magnetron opening. Food grease and splatters bake onto it and can cause arcing. This cover is a simple, inexpensive replacement.

Metal left in the microwave (a forgotten utensil, metallic packaging, or a dish with a metal trim band) also causes arcing and should be ruled out first. If arcing continues after the waveguide cover is replaced and metal is eliminated, a rack support, a damaged cavity wall, or a failing magnetron may be involved. Stop using the microwave until it's inspected. Get a sparking diagnosis →

Over-the-range microwaves double as range vent hoods — the exhaust fan pulls smoke and steam from the cooktop below. When the fan fails, the most common cause is a burned-out fan motor, which typically fails from grease accumulation over years of cooking. A failed control board can also prevent the fan from responding to controls even when the motor is intact.

Grease-saturated charcoal filters (on recirculating vent models) can also restrict airflow so severely that it appears the fan isn't working — replacing the filters is a simple maintenance task. We service over-the-range microwaves from all major brands including GE, Whirlpool, Samsung, and LG. Schedule vent fan service →

A loud humming or buzzing that's louder than normal often indicates the magnetron is beginning to fail — it may still heat but is working harder than it should and generating more noise. A grinding sound that appears when heating is active usually points to a failing high-voltage transformer or a failing magnetron bearing.

A rattling sound during operation is more likely the turntable drive system, a loose internal component, or the cooling fan blade hitting debris. Noise diagnosis benefits from a hands-on visit since the sound itself provides key diagnostic information. Book a noise diagnosis →

Unresponsive touchpads, buttons that only work intermittently, or a display that's blank or scrambled typically indicate a failing control board or user interface membrane. On older touchpad microwaves, the membrane itself degrades over time — certain buttons stop registering while others still work. This is a very common failure pattern on GE, Whirlpool, and Samsung over-the-range models after 5–8 years of use.

Error codes like F1, F3, or E-11 point to specific board or sensor failures — our technicians are trained on the diagnostic modes for all major brands. See all brands we service → Schedule a visit →