Repairing Microwave Ovens

A lot of people have written to me about repairing their own microwave oven. But, there are some safety precautions that must be observed first.

First let me tell you a short true story about my friend that tried to repair a microwave oven. He did not follow any of the listed safety precautions or technical training and was electrocuted. Thanks to rapid medical treatment and a lots prayers he was still alive. After a month in the hospital and a pacemaker installed he returned home never able to work again. When I spoke to him and asked him what had happened, he responded by saying that he new everything but forgot to follow the safety precautions. That was 35 years ago and I never forgot what happened to my friend. Do not let this happen to you. I strongly recommend that microwave oven repairs should be left up to a certified technician to repair.

WARNING: Any person who cannot use basic tools or follow written instructions should not attempt to install, maintain, or repair any microwave oven. Any improper installation, preventive maintenance, or repairs could create a risk of death, personal injury, death to others, or property damage. If you do not fully understand the installation, preventative maintenance, or repair procedures on this blog, or if you doubt your ability to complete the task on the microwave oven, do not attempt to make the repairs. Call a certified company or the manufacturer instead.

WARNING: First, before attempting any repairs, unplug the microwave. Then when you remove the outer cover or gain access to the electrical components, you must discharge the high-voltage capacitor or inverter. Do not attempt any repairs if you do not discharge the capacitor or inverter first. The high voltage circuit can have up to 5,000 volts stored in the microwave oven circuitry when the electricity is turned off.

WARNING:If you do not know how to properly and safely discharge the high-voltage capacitor or inverter, do not attempt removing or gaining access to the electrical components.

I have listed additional safety precautions below for you to follow if you attempt to make any repairs.
* Do not operate the microwave oven with the door open.
* Do not operate the microwave oven if the glass in the door is broken.
* Do not allow children under the age of 10 to operate a microwave oven.
* Do not jump out or by pass any components to operate the microwave oven.
* Do not operate the microwave oven if the door hinges and door assembly are loose.
* Always perform a microwave leakage test before and when repairs are made.
* Before you begin to service any high-voltage components within the microwave oven, you must discharge the high-voltage capacitors and inverter first.
* Never touch any wires or components with your hands or tools when the microwave oven is operating.
* Never run the microwave oven with the oven cavity empty. The microwave energy needs to be absorbed into food or a liquid, otherwise, the energy will bounce around, making its way to the high-voltage system and causing damage.

Before continuing, take a moment to refresh your memory of the safety procedures in the use and care guide that comes with your microwave oven.

Microwave oven repairs should be left up to the certified technician or the manufacturer to repair.

Preventive maintenance of the microwave oven is left up to the consumer to perform according to the use and care guide from the manufacturer. Please follow the instructions.

Refrigerators and Freezers

Refrigerator/Freezer Maintenance

The inside of the cabinet should be cleaned at least once a month to help prevent odors from building up. Of course, any spills that might happen should be wiped up immediately. Wash all removable parts by hand with warm water and a mild detergent; then rinse and dry the parts. The inside walls of the cabinet, the door liners, and the gaskets should also be washed using warm water and a mild detergent, rinsed, and dried. Never use cleaning waxes, concentrated detergents, bleaches, or cleansers containing petroleum products on plastic parts. On the outside of the cabinet, use a sponge with warm water and a mild detergent to clean dust and dirt. Then rinse off and dry thoroughly. At least two times a year, the outside cabinet should be waxed with an appliance wax or with a good auto paste wax. Waxing painted metal surfaces provides rust protection. The defrost pan, which is located behind the toe plate or behind the cabinet, should be cleaned out once a month. The condenser coil should also be cleaned of dust and lint at least once a month. The floor should be free of dirt and debris when the cabinet is rolled out away from the wall. After the cabinet is rolled back into place, you must check to be sure that the
cabinet is level.
Always follow the manufacturers use and care guide for proper maintenance and installation of your product.

Product failure

Given the information about the product’s problem, information and diagnostic charts
from my book, and the information you have read in the use and care manual, as the
servicer, you will be able to perform the following steps in sequence to diagnose and
correct a malfunction. The basic steps to follow when diagnosing an appliance or air
conditioner problem are:
1. Verify the complaint. Ask the consumer what symptoms were caused by the
problem with the appliance or air conditioner.
2. Check for external factors. For example: is the appliance or air conditioner installed
properly, does the product have the correct voltage, etc.?
3. Check for physical damage. Look for internal and external physical damage. Any
damage will prevent the appliance or air conditioner from functioning properly.
Two examples are broken parts at the base of the washing machine or a damaged
cabinet that prevents the doors from closing properly.
4. Check the controls. The controls must be set to the proper settings. If the controls
are not set correctly, the appliance or air conditioner might not function properly or
complete its cycle.
5. Operate the product. Operate the appliance or air conditioner, and let it run
through its cycle. Check the cycle operation against the operational sequence of
events that is listed in the use and care manual.
6. Is the product operating properly? If it is, explain to the consumer how to operate
the appliance or air conditioner according to the manufacturer’s specifications.
7. The product is not operating properly. If the appliance or air conditioner is not
operating properly, proceed to locate which component has failed. Check the diagnostic
charts that are listed in this book to assist you in the correct direction to take.

How to diagnose a problem

There are many different ways to diagnose a problem, but all of them basically use the
same reasoning of deduction:

• Where does the consumer think the malfunction is located within the appliance or
air conditioner?

• Where is the actual problem located within the appliance or air conditioner?

• Are there any related problems with the appliance or air conditioner?

• How can the problem with the appliance or air conditioner be solved?

For example, the consumer states that the dryer does not dry the clothes and believes
that the heating element is bad. The actual problem might be a restricted exhaust vent, a
clogged lint filter, bad heating elements, faulty operating thermostats or safety thermostat,
or improper control settings.
When checking the dryer, you might notice that the control settings are set for air drying
instead of heat drying. Thus, the actual problem was that the control settings were not
positioned correctly. The related problem is: “How did the control setting move to the air-dry
position?” This leads to the question: “Does the consumer know how to operate the dryer?” To
solve this problem, you will have to instruct the consumer in the proper operation of the dryer.
All appliances and air conditioners go through a certain sequence of events. Understanding
the proper operation and this sequence as indicated in the use and care manual is beneficial
when diagnosing the appliance or air conditioner.