Service Manual

11
1. Operation Diagnosis
1) Startup Cycle: Turn on the power supply. Move the control switch to the "ICE" position.
"on" appears on CB display. HGV energizes and Comp/AMD 30-sec. delay timer.
Note: • CB "on" display remains on unless the 10.5VAC power supply to CB CN1 is
interrupted.
• Check CB using the steps in "II.C. Control Board Check."
• Conrm BC is CLOSED. If BC is open, remove ice from BC. If no ice is around
BC and icemaker does not start, see "II.D. Bin Control Check."
a) Startup Cycle Diagnosis: If CB "on" is off, conrm 5A fuse is good. Check for
115VAC at CS #2 (DBU) to neutral (W) then at CS #1(R) to neutral (W). If 115VAC
is present on #2 (DBU) and not on #1(R), replace CS. If 115VAC is present on CS
#1 (R), check for 115VAC at HPS (R) to neutral (W) then HPS (DBU) to neutral (W).
If115VAC is present at HPS (R) and not at HPS (DBU), HPS is open.
See "b) HPS Diagnosis" below. If115VAC is present at HPS (DBU), check for
10.5VAC at CB CN1#1 red wire to CB CN2 #1 red wire. If10.5VAC is not present,
check CT continuity. If open, replace CT. If 10.5VAC is present and CB "on" display is
not on, replace CB.
b) HPS Diagnosis: If HPS is open, HPS automatically resets when refrigeration circuit
high-side pressure is within an acceptable range. If HPS does not reset (open), allow
pressures to equalize and HPS to reset. If refrigeration circuit high-side pressure
does not drop, recover, evacuate, and recharge if necessary. Before restarting the
appliance, check for dirty or clogged condenser. Once the appliance is restarted,
check:
Harvest Cycle: HGV or strainer.
Freeze Cycle: FM, TXV, drier, and fan blade for binding.
If high-side refrigerant pressures have returned to an acceptable range and HPS
does not close, replace HPS.
Conrm that the location meets installation requirements. See the appliance's
instruction manual for details.