III. Service Diagnosis

WARNING

1.This unit should be diagnosed and repaired only by qualified service personnel to reduce the risk of death, electric shock, serious injury, or fire.

2.Risk of electric shock. Use extreme caution and exercise safe electrical practices.

3.Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.

4.Do not make any alterations to the unit. This could cause water leak, electric shock, or fire.

5.To help reduce the risk of electric shock, do not touch switches with damp hands.

A.Diagnostic Procedure

The diagnostic procedure is a sequence check of the switches and sensors while operating the unit, by using the switch open/closed display mode.

Switch Open/Closed Display Mode

The switch open/closed display mode indicates when the door switch, wash tank water level sensor, internal booster tank water level float switch, and internal booster tank backup water level float switch are open or closed.

To enter the switch open/closed display mode, use the "ON/OFF" button to turn on the unit. Press and hold the up and down buttons for 3 seconds. The following appears in the display:

Close the door and start a cycle. The display indicates whether a switch is open or closed. When a switch is closed, its corresponding segment is illuminated in the display. See the illustration below.

To resume the normal display, press the down button.

Internal Booster Tank Backup Water Level Float Switch

Door Switch

Internal Booster Tank Water Level Float Switch

Wash Tank Water Level Sensor

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Hoshizaki JWE-620UA-6B service manual III. Service Diagnosis, Diagnostic Procedure, Switch Open/Closed Display Mode