Hoshizaki KM-320MAH, KM-320MWH service manual

3)Reconnect the float switch connector to the controller board. After the first 5 minutes of the freeze cycle, disconnect the float switch leads from the controller board. At this point, the unit should start the defrost cycle.

4)After step 3), de-energize the unit and confirm that the defrost timer is in the minimum position. Disconnect the resistor from the controller board and energize the unit. After the 1 minute water supply cycle, the defrost cycle starts. Re-connect a 1.5 to 3.5 kΩ resistor to connector K3 (pins #1 and #2) after the first 2 minutes of the defrost cycle. The unit should start the freeze cycle after 1 minute ± 5 seconds from the resistor connection.

c)Check the controller board using the controller board’s test program.

The output test switch "S3" provides a relay sequence test. With power OFF, place S3 ON and switch power to ICE. The correct lighting sequence should be none, 2, 3, 4, 1, and 4, normal sequence every 5 seconds. S3 should remain in the OFF position for normal operation.

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