Service Diagnosis; Diagnostic Procedure - Hoshizaki Serenity Series KMS-830MLH Service Manual

IV. Service Diagnosis
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. CHOKING HAZARD: Ensure all components, fasteners, and thumbscrews
are securely in place after the unit is serviced. Make sure that none have
fallen into the storage bin.
5. Make sure all food zones in the icemaker and dispenser unit/storage bin are
clean after the unit is serviced. For cleaning procedures, see "VI. Cleaning
and Maintenance."
A. Diagnostic Procedure
The diagnostic procedure is basically a sequence check which can be used at unit
startup or for system diagnosis. This procedure allows you to diagnose electrical system
and component failures. Before conducting the diagnostic procedure, check for correct
installation, proper voltage per unit nameplate, and adequate water supply. Check CB
using the steps in "IV.B. Control Board Check." Check the dip switch settings to assure
that S4 dip switch 3, 4, 7, 8, 9, 10 and S5 dip switch 1 through 5 are in the factory default
position. S4 dip switch 1, 2, 5, 6 are cleaning adjustments and the settings are flexible.
For factory default settings, see "II.C.3.a) Default Dip Switch Settings." As you go through
the procedure, check to assure the components energize and de-energize correctly. If
not, those components and controls are suspect. Always choose a neutral (W wire) to
establish a good neutral connection when checking voltages.
1) Turn off the power supply, then access the control box. Clear any ice from BC.
2) Turn on the power supply, then move the control switch to the "ICE" position. A 5-second
delay occurs. CB red "POWER OK" LED and green "BC CLOSED" LED turn on. If
yellow "BC OPEN" LED is on, clear ice away from BC. If bin is empty, see "IV.C.1. Bin
Control Check."
3) 1-Minute Fill Cycle – LED 4 is on. WV and X11 relay energize. After 1 minute, CB
checks for a closed F/S. If F/S is closed, harvest cycle begins. If closed, continue to
step 4. If open, WV remains energized through additional 1-minute fill cycles until water
fills the water tank and closes F/S (low water safety). Diagnosis: Confirm that water is
filling the water tank. If not, check that the water supply shut-off valve is open and WV
screen and any external filters are clear. If WV does not energize (LED 4 on), check
for 115VAC at CB K1 connector pin #6 (O wire) to a neutral (W wire). If no voltage
is present, replace CB. If voltage is present, check WV connections and solenoid
continuity. If unit fails to start harvest, check for open F/S or bad 1-minute timer in CB.
See "IV.D. Float Switch Check and Cleaning."
WARNING
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