Whirlpool Refrigerator Loud Pop and Power Loss:... | appliancefaults.com

Technical Background:

MCU Logic and Voltage Paths.

The main control unit (MCU) manages the refrigerator's functions, including compressor operation, defrost cycles, and temperature regulation. It receives power from the 120V AC supply and distributes lower voltages to various components. A sudden surge or short circuit can damage the MCU or cause it to shut down power to protect the system. Voltage paths are critical and a break in these paths can lead to complete failure. Compressor starting components like the start relay and capacitor are often weak points.

Symptoms:

US Homeowner Observations.

The homeowner reports a loud "pop" sound emanating from the Whirlpool refrigerator, followed by a complete loss of power to the appliance. No lights, no cooling, nothing.

Possible Causes:

Tripped breaker due to overload.
Short circuit in the compressor.
Faulty start relay or capacitor.
Burned wiring connection.
Malfunctioning main control board (MCU).
Defective outlet/receptacle.

Solution:

1

Unplug the refrigerator and locate the breaker panel. Reset the breaker if it's tripped. If it trips again immediately, proceed to step 2.
2

Check the outlet/receptacle with a multimeter to ensure it's providing 120V AC. If not, there's an electrical issue with the house wiring that needs addressing by a qualified electrician.
3

Disconnect power. Access the compressor compartment (usually at the back, bottom). Use a 1/4-inch nut driver to remove the access panel.
4

Visually inspect the compressor, start relay, and overload protector for signs of burning or damage. Smell for burned components.
5

Use a multimeter to test the compressor windings for shorts to ground. Resistance should be high (Megaohms). A low resistance indicates a shorted compressor.
6

If the compressor checks out, test the start relay and capacitor. Replace if faulty.
7

Inspect wiring harnesses, especially around the compressor and control board, for burned or loose connections. Repair as needed.

Safety Warning:

LOTO and High Voltage Warning.

Always disconnect power to the refrigerator before performing any repairs. Use Lock-Out/Tag-Out (LOTO) procedures to prevent accidental re-energizing of the circuit. High voltage is present in the appliance; exercise caution when working with electrical components.

Prevention:

• Regularly clean the condenser coils (located at the back or bottom) to improve airflow and reduce compressor strain. Use a condenser coil brush.
• Avoid overloading the refrigerator with food.
• Ensure the refrigerator is plugged into a dedicated circuit to prevent overload.

Expert Tip:

Trade Secret or Service Mode Sequence.

Many Whirlpool refrigerators have a service mode that allows you to run diagnostic tests and view error codes. To access the service mode, typically you have to press a combination of buttons on the control panel within a specific time frame (e.g., Door Light switch, then Freezer Temperature Down, Door Light switch, Freezer Temperature Down, Door Light switch within 5 seconds). Consult the service manual for the specific sequence for your model.

Frequently Asked Questions

•How do I test the compressor windings with a multimeter?

Set your multimeter to the Ohms setting (typically 200 Ohms or higher). Disconnect the wires from the compressor terminals. Measure the resistance between each pair of terminals (e.g., Common to Start, Common to Run, Start to Run). Note the readings. Then, measure the resistance between each terminal and the compressor body (ground). Ideally you should have a very high resistance (Megaohms) from each terminal to ground. A low resistance reading indicates a shorted winding and necessitates compressor replacement.

•What are the signs of a bad start relay or capacitor?

Visually inspect the start relay and capacitor for any signs of bulging, cracking, burning, or oil leakage. Use a multimeter to test the capacitor for capacitance using the capacitance setting. The reading should be within the specified range for the capacitor (usually printed on the component). A bad start relay may have loose or burned contacts, or show no continuity when tested with a multimeter in Ohms mode.

•If the breaker keeps tripping, what could be the issue even after replacing the start relay and capacitor?

If the breaker continues to trip after replacing the start relay and capacitor, the most likely culprit is a failing or shorted compressor. The motor windings inside the compressor could be breaking down, drawing excessive current and causing the breaker to trip. While less likely, a short in the wiring harness or a malfunctioning main control board could also cause this issue, but compressor failure is the most common reason.

Whirlpool Refrigerator Loud Pop and Power Loss: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I test the compressor windings with a multimeter?

•What are the signs of a bad start relay or capacitor?

•If the breaker keeps tripping, what could be the issue even after replacing the start relay and capacitor?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: