[D] Control Board Check Procedure; [E] Control Board Replacement - Hoshizaki KMD-270AWA Service Manual

S2 Dip Switch Setting
No. 6
OFF
ON
m) Anti-Slush Control (S2 dip switch 6) [Program Ver. 3.2]
Do not adjust. This must be left in the factory default position or the unit will not operate
properly.
When activated (Ver. 1.1), the thermistor located on the suction line checks for a 41°F (5°C)
temperature as the evaporator cools. When 41°F (5°C) is reached, a 4.8 kΩ signal causes
the control board to de-energize the pump motor for 10 seconds.
When activated (Ver. 2.0), the thermistor located on the suction line checks for a 50°F
(10°C) temperature as the evaporator cools. When 50°F (10°C) is reached, a 3.9 kΩ signal
causes the control board to de-energize the pump motor for 10 seconds and energize it for
50 seconds repeatedly. When 34°F (1°C) is reached, a 5.9 kΩ signal causes the control
board to de-energize the pump motor for 10 seconds, energize it for 50 seconds,
de-energize it again for 10 seconds, then energize it continuously.
S2 Dip Switch Setting
No. 6
OFF
ON

[d] CONTROL BOARD CHECK PROCEDURE

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.
1) Check the dip switch settings to assure that S1 dip switch 3, 4, 7, 8, 9, & 10 and S2 dip
switch 1 through 6 are in the factory default position. S1 dip switch 1, 2, 5, & 6 are
cleaning adjustments and the settings are flexible.
2) Move the control switch to the "ICE" position and check for proper control voltage. If the
"POWER OK" LED is on, the control voltage is good. If the "POWER OK" LED is off,
check the control transformer circuit. If no voltage is present, check the power supply
circuit.
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
should be 5, 6, 7, 8, 9, 4. Some components (e.g., the compressor) will cycle during the
test. Each LED flashes three times in 5 seconds. LED 5 continues to flash while LED 6
flashes. Following the output test sequence, the icemaker will resume normal operation
beginning with the 1 minute fill cycle.

[e] CONTROL BOARD REPLACEMENT

The dip switches should be adjusted to the factory default settings as outlined in this
manual.
Anti-Slush Control
Activated (Ver. 2.0)
Deactivated
Anti-Slush Control
Activated (Ver. 1.1)
Activated (Ver. 2.0)
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