Viking Microwave Plate Not Spinning: Troubleshooting... | appliancefaults.com

Technical Background:

The microwave's main control unit (MCU) sends a 120V AC signal to the turntable motor when a cooking cycle is initiated. This voltage passes through door interlock switches for safety. If any of these switches are faulty or the motor is defective, the turntable will not spin. The MCU also monitors current draw and can shut down the motor circuit if it detects a fault.

Symptoms:

The Viking microwave heats food, but the turntable plate does not rotate during the cooking cycle. This can lead to uneven heating.

Possible Causes:

Faulty turntable motor
Defective turntable motor drive coupling
Damaged or misaligned turntable support roller
Control board malfunction
Door switch interlock issue affecting motor circuit
Wiring harness issue between control board and motor

Solution:

1

Unplug the microwave from the outlet.
2

Remove the turntable plate and support roller. Inspect the support roller for debris or damage.
3

Inspect the turntable motor drive coupling for cracks or damage. Replace if necessary.
4

Using a multimeter, test the turntable motor for continuity. A typical reading should be approximately 20-50 ohms. An open circuit indicates a failed motor.
5

Check the door switches for proper operation and continuity with a multimeter. Verify they are receiving 120V AC when the door is closed.
6

If the motor fails the continuity test or the door switch voltage is incorrect, replace the faulty component. Use a 1/4-inch nut driver to remove the motor.
7

Reassemble the microwave and test the turntable function. Monitor voltage to the turntable motor during operation.

Safety Warning:

Disconnect power to the microwave before performing any repairs. Microwaves contain high-voltage components that can cause serious injury or death. Always use proper Lock Out Tag Out (LOTO) procedures. Capacitors can hold a charge even when unplugged; discharge them carefully before working on the unit.

Prevention:

Regularly clean the inside of the microwave to prevent food debris from interfering with the turntable's rotation. Avoid slamming the door, as this can damage the door switches.

Expert Tip:

Some Viking microwave models have a service mode accessible through a specific button sequence. This mode allows you to test individual components, including the turntable motor. Consult the service manual for your specific model for the exact sequence.

Frequently Asked Questions

•How do I discharge the capacitor in the microwave?

Use an insulated screwdriver with a well-insulated handle to short across the capacitor terminals. Be extremely careful and ensure you are not touching any metal parts of the screwdriver while doing this.

•Where can I find a replacement turntable motor for my Viking microwave?

You can find replacement motors at appliance parts retailers online or at local appliance repair shops. Be sure to have the model number of your microwave when ordering.

•What are the correct voltage readings for the door interlock switches?

When the door is closed, the door interlock switches should have 120V AC passing through them to the turntable motor circuit. When the door is open, the voltage should be zero. Use a multimeter to test this.

Viking Microwave Plate Not Spinning: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I discharge the capacitor in the microwave?

•Where can I find a replacement turntable motor for my Viking microwave?

•What are the correct voltage readings for the door interlock switches?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: