Hoshizaki KM-1601MRH/3 Ice Maker User Manual


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31
B. Control Board Check
Before replacing a control board 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.
AlarmReset:Ifthecontrolboardisinalarm(beeping),pressthe"ALARMRESET"button
on the control board while the control board is beeping. WARNING!Risk
of electric shock. Care should be taken not to touch live terminals.
Once reset, the unit starts at the 1-minute ll cycle. For audible alarm
information,see"II.C.2.LEDLightsandAudibleAlarmSafeties."
1) Check the dip switch settings to assure that S4 dip switch #3, 4, 7, 8, 9, & 10 and S5 dip
switch 1 through 5 are in the factory default position. S4 dip switch 1, 2, 5, & 6are
cleaning adjustments and the settings are exible. For factory default settings, see
"II.C.3.DefaultDipSwitchSettings."
2)Movethecontrolswitchtothe"ICE"position.Ifthered"POWEROK"LEDison,the
controlvoltageisgood.Ifthered"POWEROK"LEDisoff,cleariceawayfromthe
thermostatic bin control bulb in the storage bin area. If no ice is near the thermostatic
bincontrolbulborthered"POWEROK"LEDdoesnotcomeonevenafterclearing
awayice,checkthethermostaticbincontrol.See"IV.C.BinControlCheck."Ifthe
thermostaticbincontrolisokay(closed)andthered"POWEROK"LEDisoff,checkthe
fuse, control switch contacts, high-pressure switch, and control transformer secondary
circuit. Transformer output is 10.5V at 115V primary input. If the secondary circuit has
proper voltage and the red LED is off, the control board is bad and should be replaced.
If the secondary circuit does not have proper voltage, check the control transformer
primary circuit. Check for 115V at the control board K1 ten-pin connector. Check the
#10 pin (BR wire) to a white neutral wire for 115V. (Always choose a white neutral wire
to establish a good neutral connection when checking voltages.) For additional checks,
see"IV.F.1.NoIceProduction."
3)The"OUTPUTTEST"buttonprovidesarelaysequencetest.Makesurethecontrol
switchisinthe"ICE"position,thenpressthe"OUTPUTTEST"button.Thecorrect
lighting sequence is 2, 3, 4, 1. Note that the order of the LEDs from the outer edge
of the control board is 1, 4, 3, 2. Components (e.g., compressor) will cycle during the
test. Following the test, the icemaker resumes operation. If the LEDs do not light as
described above, the control board is bad and should be replaced.
4) To verify voltage output from the control board to the components, slide the control
board K1 ten-pin connector out far enough to allow multimeter lead contact. With the
unit in the cycle to be tested, check output voltage from the corresponding pin on the
control board K1 ten-pin connector to ground. If output voltage is not found and the
appropriate LED is on, the control board is bad and should be replaced.
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