Hoshizaki dcm-75ibah service manual Service Diagnosis, Ice Production Check, Diagnostic Procedure

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B. Service Diagnosis

WARNING

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

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

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

•CHOKING HAZARD: Ensure all components, fasteners, and thumbscrews are securely in place after the appliance is serviced. Make sure that none have fallen into the storage bin.

•Make sure all food zones in the appliance are clean after service. For cleaning procedures, see the instruction manual or the maintenance label.

1.Ice Production Check

To check production, prepare a bucket or pan to catch the ice and a set of scales to weigh the ice. After the appliance has operated for 10 to 20 minutes, catch the ice production for 10 minutes. Weigh the ice to establish the batch weight. Multiply the batch weight by 144 to calculate 24hr production. When confirming production or diagnosing low production, see "VIII.B. Performance Data."

2. Diagnostic Procedure

This diagnostic procedure is a sequence check that allows you to diagnose the electrical system and components. Before proceeding, check for correct installation, proper voltage per unit nameplate, and adequate water supply. Check that the 24VAC 1A fuse and GM 115VAC 3A fuse are good. When checking high-voltage (115VAC), always choose a neutral (W) to establish a good neutral connection. When checking low‑voltage (24VAC), always choose a neutral (LBU) from CT to establish a good neutral connection. When checking CB DC-voltage (5VDC), use CB red K4 connector pin closest to CB black K3 connector for DC ground (GND). CB "POWER" LED remains on unless power supply is interrupted. Check CB using the steps in "II.C. Control Board Check."

IMPORTANT! Appliance will not start unless the safety switch is engaged.

1)Turn on the power supply. Remove the front panel. Move the power switch to the "ON" position, then move the control switch to the "DRAIN" position. Engage the safety switch.

2)Allow the water system to drain for 5 minutes. If water does not drain, see step 12.

3)Disengage the safety switch, then move the control switch to the "OFF" position.

4)Move the power switch to the "OFF" position.

5)Remove the control box cover.

6)Engage the safety switch.

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Contents DCM-751BAH-OS DCM-751BWH-OS Hoshizaki AMERICA, INC Contents Page Important Safety Information Page DCM-751BAH-OS Construction and Water/Refrigeration Circuit DiagramsDCM-751BWH-OS Ice Making Unit Water/Refrigeration Circuit Diagrams Spout Inlet Water Valve Water Supply Float Chart Control Board Sequence Flow Chart DCM-751BH-OSOperation DiagnosisDiagnostic Procedure Service DiagnosisIce Production Check Page Page Page Page Control Board Check High-Pressure Switch HPS 5VDC CB K9 Connector See Fig5VDC CB K9 Connector Component Pin # Wire Color 5VDC CB K8 Connector Component Pin # Wire Color 5VDC CB K8 Connector See FigGear Motor Protect Relay Gmpr Bin Control BC5VDC 0VDC Portion Signal #5 R Red K4 pin closest 5VDC Power Supply #3 W/BK Connector Pin # Wire Color Neutral LBU Open Closed 24VAC CB K2 ConnectorBin Control Check Float Switch Check Float Switch Check and CleaningFloat Switch Cleaning Page No Ice Production Diagnostic TablesNo Ice Production Possible Cause Startup Shutdown No Ice Production Possible CauseIce Dispense-Push Button Ice/Water DispensingIce Dispense-Opti-Serve Water Dispense-Push ButtonIII. Controls and Adjustments DCM-751BH Control Board LayoutDCM-751BH-OS K2 Connector Drain Valve #10 W/BUNo. of Beeps Type of Alarm Reset Options Every 5 sec LED Lights and Audible Alarm SafetiesIcemaking Sequence Sequence Step Energized Components Min MaxDefault Dip Switch Settings Settings and AdjustmentsInfrared Sensor Shutdown Delay S1 dip switch 1, 2 Drain Frequency Control S1 dip switchBin Control Selector S1 dip switch Continuous Dispensing Timer S1 dip switch 5Bin Control Shutdown Delay S1 dip switch Factory Use S1 Dip Switch 9ICE Power Switch, Control Switch, and Dispense Mode SwitchOFF DrainContinuous Dispense Mode SwitchPortion Service for Refrigerant Lines IV. Removal and Replacement of ComponentsBrazing Refrigerant RecoveryEvacuation and Recharge R-404A Evaporator Assembly Components. See Fig Important Notes for Component ReplacementEvaporator Assembly Upper Bearing Wear Check Icemaking UnitRemoval and Replacement of Auger Removal and Replacement of Extruding HeadRemoval and Replacement of Evaporator 5b. Lower Housing Removal and Replacement of Gear Motor Dispense Auger and Agitator Dispense ComponentsDispense and Agitating Motors Maintenance Schedule MaintenanceFrequency Area Task VI. Preparing the Appliance for Periods of Non-Use Page VII. Disposal DCM-751BAH VIII. Technical Information Specification SheetsDesign without prior Potable Water WATER-COOLED Condenser DCM-751BWH779 758 Reference without *marks 738 719 ICE Production Performance Data800 363 Wiring Diagrams DCM-751BH-OS
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