[krisann1]

My GE is not cooling the refrigerator portion, so I took it apart and thawed off all the ice covering the coils. I can't find a defrost timer in the frig or in the parts list, so I assume the control board is supposed to tell the heater to turn on? My appliance repair guy has replaced the control board twice, so I'm assuming everything works fine until the ice once again closes the passage to the fresh food compartment of the frig. He doesn't look beyond the control board, apparently, and I've paid him over $500 for two repairs and two control boards. I'd really appreciate some help diagnosing the problem. Thanks!

[ApplianceJunk]

There are two other parts to the defrost system. The defrost heater and the defrost thermostat. They should both be checked before replacing the board.

[denman]

Here is a good site with info on how to test the parts
http://www.acmehowto.com/howto/appli...frigerator.php

If you do not own a meter, I would suggest you purchase a one. You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.

There is a good STICKY at the start of this forum about it's use.