Bin Control Troubleshooting; A) Machine Will Not Start; B) Machine Will Not Shut Off; Control Board Check Procedure - Hoshizaki DKM-500BAH Service Manual

shut down the unit. However, to prevent incomplete batches of ice from forming on the
evaporator, the control board will only shut down the machine within the first 5 minutes of
the freeze cycle. If ice pushes the lever in after the first five minutes of the freeze cycle,
the control board will allow the machine to complete the freeze cycle and the following
harvest cycle before shutting down the machine.
Dip switch number 7 must be in the ON position for the control board to receive input
from the bin control.

4. Bin Control Troubleshooting

a) Machine Will Not Start

1) Move dip switch no. 7 to the OFF position. If the machine starts up within a few
seconds, the bin control is the likely problem. If the machine does not start up, refer to
section "IV. Service Diagnosis" to verify that non-bin control related issues are resolved.
2) Check to make sure shipping tape has been removed and the wires are connected
properly.
3) Check to make sure no obstruction prevents the lever from moving to the bin empty
position.
4) Check proximity switch continuity to make sure it is not stuck open.

b) Machine Will Not Shut Off

1) Refer to Section "IV. Service Diagnosis" to verify that non-bin control related issues are
resolved.
2) Dip switch no. 7 should be in the ON position. If the switch is in the OFF position, the
control board will not receive input from the bin control.
3) Check to make sure no obstruction prevents the lever from moving to the bin full
position.
4) Push the lever in within the first 5 minutes of the freeze cycle. If the machine does not
shut off, check the resistance values of the resistor wire harness. You should read
approximately 15.8 KΩ between the black terminal and the red terminal that connect to
the K4 connector on the control board when the lever is in the bin full position (proximity
switch open). If this reads approximately 7.9 KΩ, the resistors may be miswired or the
proximity switch may be stuck closed. Switch the black and white wires in the terminal
housing or order a replacement wire harness. If this does not resolve the problem,
replace the bin control assembly.

5. 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 #3, 4, 7, 8, 9, & 10 are in the factory default
position. Output test switch S3 should be OFF. Switches 1, 2, 5, & 6 are cleaning
adjustments and the settings are flexible.
2) Turn the control switch to ICE and check for proper control voltage. If the red LED is ON,
the control voltage is good. If the red LED is OFF, check the control transformer circuit.
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