B. Control Module Check
Before replacing a control module that does not show a visible defect and that you suspect is bad, always conduct the following check procedure. This procedure will help you verify your diagnosis. Always choose a white (W) neutral wire to establish a good neutral connection when checking high voltages. Also, confirm that there is a good neutral connection to the control module terminal N5.
Alarm Reset: To silence the alarm, press and release the upper or lower button with power on. For alarm information, see "II.D.2. Alarm Safeties."
Startup/Cool Down:
1)Check all wiring connections. Confirm that the display module cable, cabinet thermistor, and defrost thermistor are properly connected.
2)Move the power switch to the "ON" position.
3)Check for 115VAC between control module terminals L3 and N5. If 115VAC is not present, check power supply and power switch.
4)Check that the display module is on and cabinet temperature is displayed. If not, it is recommended that both the control module and display module be replaced.
5)Freezer: Check that the evaporator fan motors are energized. Make sure that the door(s) are closed and the door switch is engaged. Next, check for 115VAC between control module terminals F6 and N5. If 115VAC is not present, the control module must be replaced.
6)Check that the compressor and condenser fan motor energize. If not, check for 115VAC between control module terminals C1 and N5. If 115VAC is not present, control module must be replaced.
Defrost:
7)Press and hold the lower button until "dEF" appears on the display module.
8)Confirm that the compressor, condenser fan motor, and evaporator fan motors (freezer) de‑energize. Check for 115VAC between control module terminals C1 and N5 for compressor and condenser fan motor, then between terminals F6 and N5 (freezer) for evaporator fan motors. If "dEF" is displayed and there is 115VAC between the terminals, control module must be replaced.
9)Freezer: Confirm that the defrost heater energizes. Check for 115VAC between control module terminals H4 and N5. If "dEF" is displayed and 115VAC is not present, control module must be replaced.
10)Check that the components restart after defrost termination.
Refrigerator: Compressor and condenser fan motor energize as soon as the defrost thermistor termination temperature is satisfied. See "Defrost Termination" under "IV.A.1.9) Defrost" and "IV.C. Thermistor Check." If components fail to start, control module must be replaced.
Freezer: Compressor and condenser fan motor energize
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