GE refrigerator defrost

[jumptrout51]

What is the procedure to initiate defrost in a ge refrigerator model # GSS20DBMDWW
It has a printed circuit board to control functions.


GE Refrigerator Main Control Board Part # WR55X10942

[Repair-man]

Here's the 31-9062 GE Refrigerator Adaptive Defrost Service Manual

Self Diagnostics
To enter Self Diagnostic mode, both temperature control panel displays must be illuminated. A display can be illuminated by pressing an adjacent temperature adjustment button. When both displays are illuminated, set the freezer and refrigerator temperature settings to 5. Simultaneously press and hold all 4 temperature adjustment buttons for approximately 3 seconds. A flashing 0 in the refrigerator and freezer displays will indicate that the refrigerator is in Self Diagnostic mode.

For temperature control panels with single-digit displays, the COLDER temperature adjustment button will increment the numbers up and the WARMER temperature adjustment button will increment the numbers down. Use the freezer temperature adjustment buttons to enter the test code number in the freezer display. Use the refrigerator temperature adjustment buttons to enter the test code number in the refrigerator display. When a test code has been entered, the displays will flash to confirm the test.
Press the HOLD button for 3 seconds to begin the test.
For temperature control panels with 3-digit displays, the COLDER temperature adjustment button will increment the numbers down and the WARMER temperature adjustment button will increment the numbers up. Use the freezer temperature adjustment buttons to enter the test code number in the freezer display.

While in the diagnostic mode set the freezer control to 1 and the refrigerator to 4 and this will initiate a defrost cycle.


Defrost system check
Does defrost heater come on?
Carefully unplug J9 blue connector from main board. Measure between blue wire on connector and neutral orange wire on main board J7. Is there approximately 27Ω? If not, the heater or bimetal is open.

Check for 120 VAC from neutral orange wire J7 to defrost terminal J9 on main board. Is 120 VAC present? Reinstall blue connector.  Measure for 120VAC at defrost heater. Is 120VAC present? Yes - Replace defrost heater
No-Check wiring harness. Check defrost thermostat


Run Service Diagnostic Test (0-7) for thermistors. Do thermistors pass test?
replace thermistor or replace main board

[jumptrout51]

The manual is interesting reading but does not answer my question. There is no troubleshooting procedure to initiate defrost.
I want to determine if I have a bad board or the defrost components ie heater tstat are defective.
Is there a procedure to force the board to defrost mode?

[jumptrout51]

Sorry. I was reading then typing when the procedural post was made. I did not see it. Thanks for the info.

[Repair-man]

I have a habit of modifying my posts afterward...you caught me too soon

[jumptrout51]

I was also thinking I could jump out the Line voltage with the defrost wire use my amp meter and look for current draw. If no current draw bad heater components. What do you think?
If the heater does work. Then a bad board.

[Repair-man]

Why do that when you can OHm the defrost heater from behind the fridge at the board?

[jumptrout51]

DUH... Thanks.