The reason I quit repairing appliances was over credit, the large super stores were popping up everywhere offering major appliances to take home with no payments for twelve months. People were falling into the trap buying new rather than call in a service technician to repair a broken down appliance.
The credit crunch has now left people in a tight spot, calling in a service tech is still a tough call when the hourly rate is so high but buying a good used working appliance now makes economic sense if the family is to have food on the table..
The most common problem with a frost free refrigerator is a malfunction of the defrost timer. The timer consists of a clock motor and a plastic cam that opens and closes contacts inside the timer. The cam is programed to run the fridge in a cooling cycle for 6 hours, the thermostat will interrupt this cycle once the temperatures inside the fridge have been reached.
After 6 hours of run time the cam inside the timer has now advanced into the defrost cycle a new set of contacts are put into service supplying power to a heating coil embedded in the aluminum fins of the evaporator coil which you will find hidden behind a tin plate easily removed inside the freezer compartment the defrost cycle which lasts 20 minutes.
Both sets of contacts inside the timer are required to handle heavy amperage loads and what happens is that the contacts will weld themselves together rendering the timers purpose ineffective.
If the timer fails during a defrost cycle the refrigerator will fail to return to the run cycle, the food inside will spoil.
Should the timer fail during the run cycle we have a different problem ice will build up on the evaporator coil which also supply's cold air via a fan into the lower portion of the fridge were we keep our beer. As the evaporator coil becomes totally encased in ice the air can no longer pass over to keep that beer cold as we like it.
When the beer warms its only natural that we turn up the thermostat to a colder position, this only works so long before we consider tossing the fridge. When ever you find a fridge with the thermostat tuned as far as it will go you can bet the defrost timer has welded contacts in the run cycle. Replace the timer and you have a good fridge to sell.
Now if you plugged in that discarded fridge and it never came on chances are the timer quit in a defrost cycle, take a wide bladed screw driver then manually advance the cam on the timer 1/4 turn, if mother luck is with you the unit will run. Replace the timer and sell the fridge.
Most places that sell appliance parts will have specials on defrost timers they are a popular item, some of the newer fridges have electronic timers which are very expensive for these check out ebay. Or wait until you come across another fridge of a similar model to cannibalize.
Another common problem is water accumulating on the bottom of the fridge, this would indicate that the tube that carries the defrosted water from the evaporator coil is no longer able to reach the evaporating tray the plastic drain tube has become clogged.
Ive seen were a bag of frozen peas has spilled out, one or more of the peas found its way into the tube clogging it, usually its mold that does the dirty work of clogging. Blow the tube with compressed air then pour a bit of diluted bleach through the line to prevent a re-occurrence.
In this short video you will note the dark sludge in the evaporating tray near the compressor which supplies the heat to evaporate the defrosted water coming off of the evaporator coil above. That mold is the cause of legionnaires.
A very good explanation on how a fridge works.
http://www.appliance-repair-it.com/H...tors-work.html
Have fun and lets get busy turning that trash into cash.
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