Service Guide

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2b) Manually-Initiated Defrost-Termination: Has DTh warmed to 45°F (7.2°C)?
Ifnot, conrm DTh status. See "II.D. Thermistor Check." If DTh is in proper range,
DHde-energizes and 2 delay timers start. If DTh has not warmed to 45°F (7.2°C),
check DT and DH continuity. Next, check DH amp draw.
(1) 3-min. Comp and EvapFM delay timers terminate: 3 min. after DH
de-energizes, conrm defrost icon turns off, Comp and EvapFM icons turn on,
and Comp, ConFM, EvapFM, MH, and PH energize. If not, conrm cabinet
temperature is warm enough for Comp and ConFM operation.
CM and Defrost Thermistor Diagnosis: Check for 115VAC at CM C1 (V) to
neutral(W). If115VAC is not present, check CTh status. See "II.D.Thermistor
Check." If CTh ohm reading is in proper range, replace CM.
MH and PH Diagnosis: Check for 115VAC at CR 0 (P and O) to neutral (W).
If 115VAC is not present, check HPS continuity. See "f) HPS Activation" above.
Comp and ConFM: Check for 115VAC at CR 0 (P and O) to neutral (W).
If115VAC is not present, check HPS continuity. See "f) HPS Activation" above.
If 115VAC is present, check for 115VAC at CR #4(BK) to neutral (W) and
CR#6(R) to neutral (W). If 115VAC is present at CR #4 (BK) to neutral (W) but
not at CR #6(R) to neutral (W), replace CR. If 115VAC is present at CR #6 (R)
and Comp or ConFM are not energized, check Comp start components, Comp
protector (internal on 1-section, external on 2-section), and Comp motor winding
continuity. If ConFM is not energized, check ConFM fan blades for binding and
motor winding continuity.
EvapFM: Conrm EvapFM icon turns on and EvapFM energizes. If not, conrm
doors are closed and DS engaged. Next, check for 115VAC at CMF5 (W/
BU) to neutral (W). If 115VAC is not present, replace CM. If 115VAC is present,
checkfor 115VAC at DSR#4(DBU) to neutral(W). If115VAC is not present,
check for 115VAC at DSR#6(W/BU) to neutral (W). If115VAC is present on
DSR #6(W/BU) to neutral (W) and not on DSR #4(DBU) to neutral (W), replace
DSR. If 115VAC is present on DSR #4 (DBU) to neutral (W) and EvapFM is not
energized, check EvapFM blades for binding and EvapFM continuity.
(2) 15-min. temperature display delay timer terminates: 12 min. after Comp,
ConFM, and EvapFM energize, "dEF" is replaced by cabinet temperature on
display. If not, replace CM.
Legend: CL–cabinet light; CLS–cabinet light switch; CM–control module;
Comp–compressor; ConFM–condenser fan motor; CR–compressor relay;
CTh–cabinet thermistor; DCD–direct current driver; DH–defrost heater; DrH–drain
heater; DSR–door switch relay; DT–defrost thermostat; DTh–defrost thermistor;
EvapFM–evaporator fan motors; HPS–high-pressure switch; MH–mullion heater;
PH–perimeter heater; TXV–thermostatic expansion valve