GE Electronic Refrigerator Defrost Problem
Hi this is Shawn from http://www.appliance-repair-it.com
Today we are going to talk about how to diagnosis a G.E. electronic refrigerator with a defrost problem.
First you must determine if you have a defrost problem or not. If there is a defrost problem the refrigerator will not cool properly. The fresh food section will be warm and the freezer section will be off a little.
Remove the back wall of the refrigerator and look at the coils. If they look like this you have a defrost problem.
There are four things that will cause these refrigerators not to defrost properly.
The main board. The defrost heater. The defrost thermostat and the evaporator thermistor.
First unplug the refrigerator and locate the main board on the back of the refrigerator.
Locate the blue plug at the bottom of the board and disconnect it.
Then located the white plug just right beside it and unplug it.
Now, place one lead of your ohm meter in the center plug of the blue connector.
On the board it should be marked defrost or J9.
Now, take your other lead and place it on the pin farthest left on the orange/white wire. You should get continuity. In this case I get 21 ohms.
I got roughly 21 ohms. If it is open you know that the defrost heater or the defrost thermostat is bad.
Nine times out of ten it's going to be the heater.
If your heater and thermostat check ok next check your evaporator thermistor.
Locate the J1 connector on the main board and unplug it.
Now your ready for testing on the main board. Set your meter to read 16 thousand ohms.
I'm setting mine on 20K. Now, on the J1 plug that we already disconnected place your black lead in the fifth wire.
and your read lead on the fourth wire.
You should get 16.3 K ohms, plus or minus 5%.
Please note that this test must be done before you melt the ice on the coils.
If not you will not get the 16.3 K ohms as described.
If on the very first test we did you got open or very high resistance you will need to know if the heater of the thermostat is bad.
Melt the ice on the coils.
Remove the heater from the bottom of the coils and unplug it.
Now, test for continuity across the heater by placing one lead on one terminal and the other lead on the other terminal.
I get roughly 21 ohms, the same as the first test.
If you heater checks out ok, but you had a open circuit when you tested at the main board you know that the defrost thermostat is bad, replace it.
This is defrost thermostat. If you did not get continuity in the very first test, but the heater checks ok replace the defrost thermostat.
Please note that there is no need to check the thermistor if the heater and the thermostat are open.
If they are open you know that they are bad and most likely cause the problem.
Skip to the last test to see if the heater or the thermostat is the problem.
Note that if the heater, thermostat and thermistor all check out ok replace the main board.