Diagnostic Procedure - Hoshizaki F-500BAJ Service Manual

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 appliance nameplate, and adequate water pressure (10 PSIG to 113 PSIG).
Note: • When checking high voltage (115VAC), always choose a neutral (W) wire to
establish a good neutral connection.
• When checking low voltage (24VAC), always choose a neutral (LBU) wire to
establish a good neutral connection.
• When checking control board DC voltage (5VDC), always place the red positive
test lead from the multimeter to CB K5 pin closest to CB K4 connector.
See "II.C. Control Board Check."
• To speed up the diagnostic process, the 5-min. ice purge cycle may be bypassed
by pressing the "SERVICE" button on the control board after the gear motor
starts. WARNING! Risk of electric shock. Care should be taken not to touch
live terminals.
• If the icemaker is in alarm, see "III.A.2. LED Lights and Audible Alarm Safeties."
• CB monitors the following switches with 5VDC during the icemaking process:
Control Switch (CS), High-Pressure Switch (HPS), Float Switch (FS),
Compressor Control Relay (CCR), and Bin Control (BC). When 5VDC is present
across any of these switches, the switch is open.
1) Remove the front panel, then move the power switch to the "OFF" position. Move the
control switch to the "DRAIN" position, then move the power switch back to the "ON"
position. Replace the front panel in its correct position.
2) Allow the water system to drain for 5 min.
3) Remove the front panel and move the power switch to the "OFF" position, then unplug
the appliance from the electrical outlet (F-300BAJ) or turn off the power supply
(F-500BAJ).
4) Remove the control box cover and access CB.
5) Check the CB S1 dip switch settings, see "III.B.1. Default Dip Switch Settings" to assure
that they are in the correct positions. For proper operation of BC, confirm that S1 dip
switch 7 is in the "OFF" position.
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