LG Microwave Turntable Motor Replacement

Knowing what the motor is helps you rule it in or out. It is a small synchronous AC motor — a few watts, turning at roughly five to six RPM — that drives the glass plate through a three-prong coupler and a roller-guide ring. It runs on 120V from the control board whenever a cycle is active, with no speed control: it either spins at its fixed speed or not at all, and it reverses direction periodically so the coupler does not bind.

Motor failure vs. everything else#

It is the motor when:

• the turntable does not rotate at all during cooking
• the motor hums but the plate stays put (a stripped shaft)
• the motor clicks or buzzes without spinning (seized bearings)

It is not the motor when:

• the plate turns intermittently — debris in the coupler or roller-guide track
• the plate rocks or wobbles — worn roller-guide wheels or a cracked glass plate
• food heats unevenly even though the plate spins — a stirrer or magnetron issue, not the turntable
• the plate sits crooked — a broken three-prong coupler

The parts#

The turntable drivetrain is a small family of cheap components: the motor itself (6549W1S017A), the three-prong drive coupler (4370W1A006D), and the roller-guide support ring (5889W2A015B). The glass plate is model-specific. Before ordering a motor, inspect the coupler and roller guide — if a coupler prong is broken the plate will not turn even with a perfect motor, and if the roller-guide wheels are cracked or the track is packed with food, the plate binds and stalls a healthy motor.

Replacing the motor#

1. Unplug the microwave.
2. For a countertop unit, flip it carefully upside down (they are heavy); for an over-the-range unit, you can often reach the motor from below, or you may need to drop it off the wall mount.
3. Remove the bottom panel screws (usually four to six Phillips).
4. Find the motor at the center of the bottom panel, its shaft pointing up through the cavity floor, and unplug the two-wire connector.
5. Remove the two or three mounting screws and pull the motor down and out.
6. Fit the new motor, reconnect the wires, and refit the bottom panel.
7. Set the microphone right-side-up, replace the coupler, roller guide, and glass plate, and run a 30-second cycle to confirm smooth rotation.

Tools are minimal — a Phillips #2 for the panel, and optionally a multimeter to check motor continuity.

Living with a dead turntable and preventing repeats#

You can keep using the microwave with a stalled turntable — just pause and rotate the food by hand partway through — but fix it when practical, since the motor is inexpensive and the job is simple. To keep the new one healthy, keep the coupler and roller-guide track clean, because trapped food is what makes a plate bind and forces the motor to work against resistance until its bearings give out. If the plate wobbles rather than refusing to turn, suspect the roller-guide wheels or a chipped glass plate before the motor — replacing a motor that was never the problem is the most common wasted repair here. If your model is over-the-range and stacked above a range, make sure the microwave is fully unplugged and cool before you flip or drop it, and get a second person for the lift — these units are heavier than they look, and a slip during removal can crack the very glass plate you are trying to protect.