Hoshizaki FD-650MAH-C User manual

Hoshizaki
“A Superior Degree
of Reliability”
www.hoshizaki.com
Models
FD-650MAH-C, MWH-C, MRH-C
Modular Flaker
Hoshizaki America, Inc.
Number: 73199
Issued: 11-3-2014
SERVICE MANUAL

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WARNING
Only qualied service technicians should install and service the appliance. To
obtain the name and phone number of your local Hoshizaki Certied Service
Representative, visit www.hoshizaki.com. No service should be undertaken until
the technician has thoroughly read this Service Manual. Failure to service and
maintain the appliance in accordance with this manual will adversely affect safety,
performance, component life, and warranty coverage and may result in costly water
damage. Proper installation is the responsibility of the installer. Product failure or
property damage due to improper installation is not covered under warranty.
Hoshizaki provides this manual primarily to assist qualied service technicians in the
service of the appliance.
Should the reader have any questions or concerns which have not been satisfactorily
addressed, please call, send an e-mail message, or write to the Hoshizaki Technical
Support Department for assistance.
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
HOSHIZAKI AMERICA, INC.
618 Highway 74 South
Peachtree City, GA 30269
Attn: Hoshizaki Technical Support Department
NOTE: To expedite assistance, all correspondence/communication MUST include the
following information:
• Model Number
• Serial Number
• Complete and detailed explanation of the problem.

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CONTENTS
Important Safety Information ................................................................................................. 5
I. Construction and Water/Refrigeration Circuit Diagram ....................................................... 7
A. Construction.................................................................................................................. 7
1. Air-Cooled Models (MAH-C)..................................................................................... 7
2. Water-Cooled Models (MWH-C) .............................................................................. 8
3. Remote Models (MRH-C) ........................................................................................ 9
4. Ice Making Unit...................................................................................................... 10
B. Water/Refrigeration Circuit Diagram.............................................................................11
1. Air-Cooled Models (MAH-C)....................................................................................11
2. Water-Cooled Models (MWH-C) ............................................................................ 12
3. Remote Models (MRH-C) ...................................................................................... 13
II. Sequence of Operation and Service Diagnosis............................................................... 14
A. Sequence of Operation Flow Chart............................................................................. 14
B. Service Diagnosis ....................................................................................................... 15
C. Control Board Check................................................................................................... 18
D. Bin Control Check ....................................................................................................... 23
E. Float Switch Check and Cleaning ............................................................................... 25
1. Float Switch Check ................................................................................................ 25
2. Float Switch Cleaning............................................................................................ 25
F. Diagnostic Tables......................................................................................................... 27
III. Controls and Adjustments............................................................................................... 29
A. Control Board Layout .................................................................................................. 30
B. LED Lights and Alarm Safeties ................................................................................... 31
C. Settings and Adjustments............................................................................................ 32
1. Default Dip Switch Settings .................................................................................... 32
2. Bin Control Shutdown Delay (infrared sensor) (S1 dip switch 1, 2, 3) ................... 32
3. Drain Frequency Control (S1 dip switch 4) ............................................................ 33
4. Continuous Dispensing Timer (S1 dip switch 5 & 6).............................................. 33
5. Bin Control Selector (S1 dip switch 7) ................................................................... 33
6. Bin Control Shutdown Delay (mechanical) (S1 dip switch 8)................................. 33
7. Factory Use (S1 dip switch 9 & 10) ........................................................................ 33
D. Switches...................................................................................................................... 34
1. Power Switch.......................................................................................................... 34
2. Control Switch........................................................................................................ 34
IMPORTANT
This manual should be read carefully before the appliance is service. Read
the warnings and guidelines contained in this manual carefully as they provide
essential information for the continued safe use, service, and maintenance of the
appliance. Retain this manual for any further reference that may be necessary.

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IV. Refrigeration Circuit and Component Service Information.............................................. 35
A. Refrigeration Circuit Service Information .................................................................... 35
B. Component Service Information.................................................................................. 38
1. Upper Bearing Wear Check ................................................................................... 39
2. Removal and Replacement of Extruding Head...................................................... 39
3. Removal and Replacement of Auger ..................................................................... 40
4. Removal and Replacement of Evaporator ............................................................. 40
5. Removal and Replacement of Mechanical Seal and Lower Housing ................... 42
6. Removal and Replacement of Gear Motor ............................................................ 43
V. Maintenance .................................................................................................................... 44
VI. Preparing the Icemaker for Periods of Non-Use............................................................. 46
VII. Disposal......................................................................................................................... 48
VIII. Technical Information.................................................................................................... 49
A. Specication and Performance Data........................................................................... 49
1. FD-650MAH-C (air-cooled) .................................................................................... 49
2. FD-650MWH-C (water-cooled) .............................................................................. 50
3. FD-650MRH-C (remote air-cooled)........................................................................ 51
B. Wiring Diagrams.......................................................................................................... 52

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Important Safety Information
Throughout this manual, notices appear to bring your attention to situations which could
result in death, serious injury, damage to the appliance, or damage to property.
WARNING Indicates a hazardous situation which could result in death or
serious injury.
NOTICE Indicates a situation which could result in damage to the
appliance or property.
IMPORTANT Indicates important information about the use and care of the
appliance.
WARNING
The appliance should be destined only to the use for which it has been expressly
conceived. Any other use should be considered improper and therefore dangerous.
The manufacturer cannot be held responsible for injury or damage resulting from
improper, incorrect, and unreasonable use. Failure to service and maintain the
appliance in accordance with this manual will adversely affect safety, performance,
component life, and warranty coverage and may result in costly water damage.
To reduce the risk of death, electric shock, serious injury, or re, follow basic
precautions including the following:
• Only qualied service technicians should install and service the appliance.
• The appliance must be installed in accordance with applicable national, state, and
local codes and regulations. Failure to meet these code requirements could result in
death, electric shock, serious injury, re, or damage to the appliance.
• Electrical connection must be hard-wired and must meet national, state, and local
electrical code requirements. Failure to meet these code requirements could result
in death, electric shock, serious injury, re, or damage.
• The icemaker requires an independent power supply of proper capacity. See the
nameplate for electrical specications. Failure to use an independent power supply
of proper capacity can result in a tripped breaker, blown fuse, damage to existing
wiring, or component failure. This could lead to heat generation or re.
• THE ICEMAKER MUST BE GROUNDED. Failure to properly ground the icemaker
could result in death or serious injury.
• To reduce the risk of electric shock, do not touch the power switch or control switch
with damp hands.
• Move the power switch to the "OFF" position and turn off the power supply before
servicing. Place the disconnect (if applicable) in the off position. Lockout/Tagout to
prevent the power supply from being turned back on inadvertently. Power switch in
"OFF" position does not de-energize all loads.
• Do not place ngers or any other objects into the ice discharge opening.
• Do not make any alterations to the appliance. Alterations could result in electric
shock, injury, re, or damage.

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WARNING, continued
• The appliance is not intended for use by persons (including children) with reduced
physical, sensory, or mental capabilities, or lack of experience and knowledge,
unless they have been given supervision or instruction concerning use of the
appliance by a person responsible for their safety.
• Children should be properly supervised around the appliance.
• Do not climb, stand, or hang on the appliance or allow children or animals to do so.
Serious injury could occur or the appliance could be damaged.
• Do not use combustible spray or place volatile or ammable substances near the
appliance. They might catch re.
• Keep the area around the appliance clean. Dirt, dust, or insects in the appliance
could cause harm to individuals or damage to the appliance.
Additional Warning for Remote Models
• THE REMOTE CONDENSER UNIT MUST BE GROUNDED. The power supply and
ground connection to the remote condenser unit are supplied from the icemaker.
Failure to properly ground the remote condenser unit could result in death or
serious injury.
• Wire routing (conduit) and disconnect (if required) must meet national, state, and
local electrical code requirements. Failure to meet these code requirements could
result in death, electric shock, serious injury, re, or damage.
• Move the icemaker power switch to the "OFF" position and turn off the power supply
to the icemaker before servicing the remote condenser unit. Lockout/Tagout to
prevent the power supply from being turned back on inadvertently.
NOTICE
• Follow the instructions in this manual carefully to reduce the risk of costly water
damage.
• In areas where water damage is a concern, install in a contained area with a oor
drain.
• Install the appliance in a location that stays above freezing. Normal operating
ambient temperature must be within 45°F to 100°F (7°C to 38°C).
• Do not leave the icemaker on during extended periods of non-use, extended
absences, or in sub-freezing temperatures. To properly prepare the icemaker for
these occasions, follow the instructions in "VI. Preparing the Icemaker for Periods of
Non-Use."
• Do not place objects on top of the appliance.
• The dispenser unit/ice storage bin is for ice use only. Do not store anything else in
the dispenser unit/ice storage bin.

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I. Construction and Water/Refrigeration Circuit Diagram
A. Construction
1. Air-Cooled Models (MAH-C)
Inlet Water Valve
Thermostatic
Expansion
Valve
Control Box
Air-Cooled
Condenser
Spout
Evaporator
Gear Motor
Compressor
Fan Motor
Ice Chute
Bin Control
(Infrared Sensor)
Drier
Drain Valve

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2. Water-Cooled Models (MWH-C)
Inlet Water Valve
Thermostatic
Expansion
Valve
Control Box
Water-Cooled
Condenser
Spout
Evaporator
Gear Motor
Compressor
Water
Regulating
Valve
Ice Chute
Bin Control
(Infrared Sensor)
Drier
Drain Valve

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3. Remote Models (MRH-C)
Inlet Water Valve
Thermostatic
Expansion
Valve
Control Box
Accumulator
Spout
Evaporator
Gear Motor
Compressor
Reciever
Ice Chute Bin Control
(Infrared Sensor)
Drain Valve

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4. Ice Making Unit
Cutter
Extruding Head
(Upper Bearing)
Auger
Cylinder
Mechanical Seal
"O"-Ring
Housing (Lower Bearing)
Spline Coupling
Gear Motor
Hex Bolt
Insulation
Seal Bolt
Socket Head Cap Screw

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B. Water/Refrigeration Circuit Diagram
1. Air-Cooled Models (MAH-C)
Drier
Air-Cooled
Condenser
Condenser
Fan Motor
High-Pressure Switch
Compressor
Water Circuit
Refrigerant Circuit
Overow Hose
Reservoir
Gear Motor
Drain Valve
Thermostatic
Expansion Valve
Spout
Water Level
Evaporator
Float Switch
Inlet Water Valve
Water Supply
Drain Pan
To Drain
Drain Hose

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2. Water-Cooled Models (MWH-C)
Drier
Water-Cooled
Condenser
High-Pressure Switch
Compressor
Water Circuit
Refrigerant Circuit
Reservoir
Gear Motor Drain Valve
Thermostatic
Expansion Valve
Spout
Water Level
Evaporator
Float Switch
Inlet Water Valve
Water Supply
Drain Pan
To Drain
Water
Regulating
Valve
Cond.
Water
Outlet
Cond.
Water
Inlet
Overow Hose
Drain Hose

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3. Remote Models (MRH-C)
Drier
Air-Cooled
Condenser
Condenser
Fan Motor High-Pressure Switch
Compressor
Water Circuit
Refrigerant Circuit
Reservoir
Gear Motor Drain
Valve
Thermostatic
Expansion
Valve
Spout
Water Level
Evaporator
Float Switch
Inlet Water Valve
Water Supply
Drain Pan
To Drain
Remote Condenser Unit
Headmaster
(C.P.R.)
Receiver
Coupling
Coupling
Overow Hose
Drain Hose
Accumulator

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1-in-1 drain cycle. DV opens for 2 seconds every hour (S1 Dip Switch 4). Icemaker status does not change.
"F-A" Control Board Operation Flow Chart
LFS closed UFS closed FT reset WV de-energized
3. 1-in-12 Drain Cycle & Restart (optional)
3.Icemaker Off
UFS open LFS open (WV on) FT starts (90 sec.) WV energized Comp continues FM/FMR continues GM continues
1. Startup
2. Ice Purge Cycle
WV energized FT starts (90 sec.)
Comp energized FM/FMR continues GM continues
Power Switch "ON" Control Switch in "ICE" "POWER OK" LED on BC Green LED on BC Yellow LED off
2. Bin Control Shutdown & Restart (infrared sensor)
1. Bin Full
BC activated or DC starts Comp de-energized FM/FMR continues GM continues
1. Fill Cycle 3. Freeze Cycle
LFS closed UFS closed FT resets WV de-energized Comp continues FM/FMR continues GM continues
Low Water Safety
UFS open WV energized FT exceeded 1-beep alarm sounds Comp de-energized FM/FMR continues GM continues
DV energized (DC only) FM/FMR de-energized GM de-energized
2.Ice Purge Cycle
10-min. DT reset (DC only)
DV de-energized (DC only) 1-in-12 DT reset (DC only)
BC Green LED on BC Yellow LED (ashing or steady)
BC delay determined by S1 dip switch
1, 2, 3
4. Icemaker Restart
5 minutes
4. Icemaker Restart
2.Ice Purge Cycle 3.10-Minute
Drain
Legend: BC-bin control (infrared sensor) CB-control board Comp-compressor DC-drain cycle DT-drain timer DV-drain valve FM-fan motor FMR-fan motor-remote FT-ll timer (low water safety) GM-gear motor
LFS-lower oat switch PT-purge timer UFS-upper oat switch WV-water valve
If Fill> 90 sec. FT 1-beep alarm sounds WV continues When UFS closes alarm resets and 2. Ice Purge Cycle starts.
Maximum 90 seconds
4. 1-in-12 Drain Cycle - Although the factory default 1-in-1 drain cycle is recommended, a 1-in-12 drain cycle is available. For 1-in-12 drain cycle sequence, see "3. 1-in-12 Hour Drain Cycle & Restart (optional)."
Rell
FT Maximum 90 seconds
90 sec. FT exceeded 1-beep alarm sounds 90 sec. PT begins
When UFS closes, alarm resets and 2. Ice Purge Cycle starts.
1-beep alarm continues WV continues FM/FMR de-energized GM de-energized
BC Green LED on BC Yellow LED off
BC Green LED on BC Yellow LED off
1.DT Initiates DC
To bypass, press CB "SERVICE" button after GM starts.
5 minutes
to "2. Ice Purge Cycle" above
to "1. Fill Cycle" above
90 seconds
(S1 dip switch 4)
FT reset (90 sec.)
FT exceeded
PT terminates
30 sec.
GM energized FM/FMR energized
II. Sequence of Operation and Service Diagnosis
A. Sequence of Operation Flow Chart
UFS open
FT exceeded

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B. Service Diagnosis
WARNING
• The appliance should be diagnosed and repaired only by qualied service
personnel to reduce the risk of death, electric shock, serious injury, or re.
• Risk of electric shock. Use extreme caution and exercise safe electrical practices.
Power switch in "OFF" position does not de-energize all loads.
• 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 icemaker and dispensing unit/ice storage bin are
clean after service.
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 for the total production in 24 hours. When conrming production
or diagnosing low production, reference production information found in "VIII.A.
Specication and 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 appliance nameplate, and adequate water pressure (10 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.
• 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.
1) Conrm power supply is on and power switch is in the "ON" position.
2) Move the control switch to the "DRAIN" position.
Diagnosis "POWER OK" LED: Check that CB "POWER OK" LED is on. If not,
check for 115VAC at control transformer brown (BR) wire to neutral (W). If 115VAC is
not present, check the power switch and breaker. If 115VAC is present, check control
transformer continuity. Replace as needed. Next, check for 24VAC at control transformer
red (R) wire to neutral (LBU). If 24VAC is not present, check control transformer
continuity. Replace as needed. If 24VAC is present, check 24VAC 1A fuse. If fuse is
good, check for 24VAC at CB K8 #1 (W/R) to CB K8 #2 (LBU). If 24VAC is present and
"POWER OK" LED is off, replace CB.

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Diagnosis DV: If DV does not energize, check for 24VAC at CB K2 #10 (W/BU) to
neutral (LBU). If24VAC is not present, check control switch continuity. If open while in
the "DRAIN" position, replace control switch. If closed, check for 0VDC at CB
K9 #1(W/BK)to K9 #2 (W/BK). If5VDC is present and control switch is closed, replace
CB. If DV energizes (24VAC present at CB K2 #10 (W/BU) to neutral (LBU)), and water
does not drain, check for restricted DV and DV solenoid continuity. Clean or replace as
needed.
Diagnosis BC: Conrm green LED is on. If not and yellow LED is on or ashing, move
ice away from BC sensor. If no ice is present, clean the BC sensor lens with a warm,
clean damp cloth. If cleaning the lens does not work, see "II.D. Bin Control Check."
3) After all of the water has drained, move control switch to the "ICE" position.
CB "POWER OK" LED and BC green LED are on.
4) Fill Cycle – "WTRIN" LED is on. WV energizes. 90-sec. low water safety timer begins.
LFS closes. Nothing occurs at this time. Reservoir continues to ll until UFS closes.
Once UFS closes, 90-sec. low water safety timer terminates and 30-min. freeze timer
starts. WV de-energizes. Diagnosis: Check that "WTRIN" LED turns on and water
lls the reservoir. If not, check for water supply line shut-off valve closed, restricted
water lters, and restricted WV screen. Next, check for 24VAC at CB K2 #8(O) to
neutral(LBU). If 24VAC is not present, replace CB. If 24VAC is present, turn off the
power switch, disconnect the WV wires and check WV solenoid continuity. Ifopen,
replace WV. Reconnect WV wires, move the power switch to the "ON" position, then
check that DV is not leaking by. Conrm that WV shuts off when UFS closes.
Note: Low Water Safety– If UFS remains open 90 sec. after WV energizes, a 1-beep
alarm sounds. This alarm resets automatically once UFS closes.
5) Ice Purge Cycle – "GM" LED is on. 30-sec. GM delay timer starts. WV de-energizes
and "WTRIN" LED turns off. Once the 30-sec. GM delay timer terminates, GM, FM/
FMR, and CDR energize. CDR cannot energize unless GM circuit is complete (fuse,
internal protector, and motor windings). Once CDR energizes, CB K9 #5 (W/O) and
CB K9 #6 (W/O) 5VDC circuit closes and 5-min. ice purge timer starts. See "II.C.3)
c. Compressor Delay Relay (5-min. Ice Purge Timer Circuit)." If CDR de-energizes,
CBK9#5 (W/O) and CB K9 #6 (W/O) circuit opens, an 8-beep alarm occurs. See"III.B.
LED Lights and Alarm Safeties." Note: To bypass ice purge cycle and go straight to
freeze cycle, press CB "SERVICE" button during 30 sec. GM delay time.
Diagnosis CB: Check that UFS closed, WV LED turned off and WVde-energized.
IfUFS is closed, "WV" LED is off, and "GM" LED is off, replace CB. If "GM" LED is
on and GM is off, conrm 115VAC at CB K1 #2 (BR) to neutral(W). If115VAC is not
present, check for loose connection from power switch. If 115VAC is present, check for
115VAC at CB K1 #3 (R) to neutral (W). If115VAC is not present, replace CB.
Diagnosis GM: If115VAC is present at CB K1 #3 (R) to neutral(W), check GM fuse,
GM capacitor, GM windings, and GM coupling between auger and GM.
Diagnosis CDR: Once GM energizes, check for 115VAC at CDR #7 (O) to neutral
(W). If 115VAC is present and CDR contacts #3 (W/O) and #5 (W/O) do not close,
replace CDR. See "II.C.3)c. Compressor Delay Relay (5-min. Ice Purge Timer Circuit)."
Diagnosis FM/FMR: If115VAC is present at CB K1 #3 (R) to neutral(W) and
FM/FMR does not energize, check FM/FMR capacitor, windings, and bearings.

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6) Freeze Cycle – "COMP" LED is on. 5-min. ice purge timer terminates or CB
"SERVICE" button pressed. "COMP" LED is on. "GM" LED remains on. Comp
energizes. GM, FM/FMR, and CDR continue. Ice production begins 4 to 6 minutes after
Comp energizes depending on ambient and water conditions.
Diagnosis Comp: Check that "COMP" LED is on and that Comp energizes.
If"COMP" LED is off, conrm 5-min. ice purge timer has terminated. Check for 0VDC
across CB K9 #3 (Y) and CB K9 #4 (Y). If 5VDC is present, HPS contacts are open.
Ifhigh-pressure switch is open, CB sounds a 3-beep alarm. See "III.B. LED Lights and
Alarm Safeties." If HPS is closed, check for 115VAC at CDR #7 (O) to CDR #8(W).
If115VAC is present, check CDR continuity between CDR #3 (W/O) and CDR #5(W/O).
If open, replace CDR. If closed and"COMP" LED remains off, replace CB. If"COMP"
LED is on and Comp is off, check for 115VAC at CB X1 (BR) wires to neutral(W).
If115VAC is present on one and not the other, replace CB. If 115VAC is present on both,
check Comp windings, start relay, and capacitors.
Note: If CDR de-energizes, CB K9 #5 W/O and CB K9 #6 W/O circuit opens, Comp
de-energizes and an 8-beep alarm occurs. See "III.B. LED Lights and Alarm Safeties."
7) Rell Cycle/Low Water Safety Cycle – As ice is produced, the water level in the
reservoir drops. UFS opens. Nothing occurs at this time. When LFS opens, WV
energizes, 90-sec. low water safety timer (ll timer) starts. Comp, GM, and FM/FMR
continue. When UFS closes, WV de-energizes, 90-sec. low water safety timer (ll timer)
terminates and 30-min. freeze timer resets. If UFS remains open 90 sec. after WV
energizes (ll timer exceeded), a 90-sec. shutdown cycle starts. Comp de-energizes and
CB signals a 1-beep alarm every 5 sec. 90-sec. ice purge timer starts. GM and
FM/FMR continue. 90-sec. purge timer terminates, GM and FM/FMR de-energize.
WVand 1-beep alarm continue until UFS closes. Diagnosis – Check that "WTRIN" LED
is on. If not, check LFS. See "II.E. Float Switch Check and Cleaning." If LFS is open and
"WTRIN" LED is off, replace CB. If "WTRIN" LED is on, check that the reservoir lls.
If not, check the water supply line, restricted water lters, WV solenoid, restricted WV
screen. If WV is energized and rell exceeds 90-sec. low water safety timer (ll timer),
check DV leaking by, UFS open. See "II.E.Float Switch Check and Cleaning."
Note: Each time UFS closes, 30-min. freeze timer starts. The 30-min. freeze timer resets
when UFS closes again. If UFS does not close again within 30 min., CB shuts
down the unit and sounds a 5-beep alarm every 5 sec. See "III.B. LED Lights and
Alarm Safeties."
10) Shutdown – Use an object to cover BC sensor at the bottom of the icemaker. If the
bottom of the icemaker is not accessible in your application, remove the thumbscrew
securing BC housing, remove the housing from the base, then cover BC sensor.
Theyellow LED on BC sensor turns on (ashing or steady). The yellow LED ashes
when ice is at the outer limit of its range and turns steady as ice nears. After the
yellow LED turns on (ashing or steady), BC shutdown delay timer starts. When the
BC shutdown delay timer terminates, CB shuts down icemaker. See "II.D. Bin Control
Check."
Legend: BC–bin control; CB–control board; CDR–compressor delay relay;
Comp–compressor; DV–drain valve; FM–fan motor; FMR–fan motor-remote;
GM–gear motor; LFS–lower oat switch; UFS–upper oat switch; WV–inlet water
valve

18
C. Control Board Check
Before replacing a control board that does not show a visible defect and that you suspect
is bad, always conduct the following check procedure. This procedure will help you verify
your diagnosis.
Before diagnosing the control board drain the reservoir.
1) Check CB S1 dip switch settings to assure that they are in the factory default position.
For factory default settings, see "III.C.a) Default Dip Switch Settings."
2) Move the power switch to the "ON" position and move the control switch to the "ICE"
position. The "POWER OK" LED turns on. Diagnosis "POWER OK" LED Off: Check
for 115VAC at control transformer brown (BR) wire to neutral (W). If 115VAC is not
present, check the power switch and breaker. If 115VAC is present, check for 24VAC at
control transformer red (R) wire to neutral (LBU). If 24VAC is not present, check control
transformer continuity. Replace as needed. If 24VAC is present, check 24VAC 1A fuse.
If fuse is good, check for 24VAC at CB K8 #1 (W/R) to CB K8 #2 (LBU). If 24VAC is
present and "POWER OK" LED is off, replace CB.

19
3) CB 5VDC Output: Control Switch, High-Pressure Switch, Compressor Delay Relay,
and Float Switch. When checking 5VDC voltage, always place the red positive test lead
from the multimeter to CB K5 pin closest to CB K4 connector. See Fig. 1. Then place
the black negative test lead from the multimeter to the corresponding pin to complete
the 5VDC check. If the icemaker is in alarm (beeping), see "III.B. LED Lights and Alarm
Safeties."
a. Control Switch: When in the "ICE" position, control switch contacts are open and
5VDC is present at CB K5 pin closest to CB K4 connector to CBK9 #1 (W/BK).
If5VDC is not present, conrm the control switch is in the "ICE" position, then check
control switch continuity (open). If 5VDC is still not present, replace CB. When the
control switch is in the "DRAIN" position, the control switch contacts are closed and
0VDC is present at CB K5 pin closest to CB K4 connector to CB K9 #2 (W/BK).
If5VDC is present, conrm the control switch is in the "DRAIN" position and check
control switch continuity (closed). If 0VDC is still not present, replace CB.
b. High-Pressure Switch: When the high-pressure switch is closed, 0VDC is present at
CB K5 pin closest to CB K4 connector to CBK9 #3 (Y) and CB K9#4(Y). If0VDC is
not present and high-pressure switch is closed, replace CB. Ifhigh-pressure switch
is open, CB sounds a 3-beep alarm. See, "III.B. LED Lights and Alarm Safeties."
c. Compressor Delay Relay (5-min. Ice Purge Timer Circuit): Gear motor energizes,
energizing compressor delay relay and starting 5-min. ice purge timer. When
de-energized, 5VDC is present at CB K5 pin closest to CB K4 connector to CB
K9 #5(W/O). If 5VDC is not present, replace CB. When compressor delay relay
energizes, compressor delay relay #3 (W/O) and #5 (W/O) close and 0VDC is
present at CB K5 pin closest to CB K4 connector to CB K9 #5 (W/O). If 5VDC is
present, compressor control relay #3(W/O) and #5 (W/O) are open. If compressor
delay relay de-energizes after gear motor starts, an 8-beep alarm occurs. See "III.B.
LED Lights and Alarm Safeties."
Red positive test lead to
K5 pin closest to
K4 connector
Control Board K9 Connector
Red Positive
Test Lead
Black Negative
Test Lead
Multimeter
5VDC
Control Switch
white/black (W/BK)
High-Pressure Switch
yellow (Y)
Compressor Delay Relay
white/orange (W/O)
CB K9 Connector
Fig. 1

20
d. Float Switch: See Fig. 2. 5VDC is present at CB K5 pin closest to CB K4 connector
to CB K8#5 (BK). If5VDC is not present, replace CB. When UFS and LFS are open,
5VDC is present at CB K8 #5 (BK) to K8 #6 (R) (UFS) and K8 #7 (DBU) (LFS).
When UFS and LFS are closed, 0VDC is present at CB K8 #5 (BK) to K8#6(R)
(UFS) and K8 #7 (DBU) (LFS). For further oat switch diagnostics, see"II.E. Float
Switch Check and Cleaning."
Fig. 3
Red Positive
Test Lead
Black Negative
Test Lead
20VDC
Multimeter
Bin Control Sensor (20VDC)
Open (yellow LED ashing or steady)
20VDC DBU to BR
0VDC DBU to W
20VDC W to BR
Bin Control Sensor (20VDC)
Closed (green LED on)
20VDC DBU to BR
20VDC DBU to W
0VDC W to BR
Brown (BR)
Dark Blue (DBU)
White (W)
• K6 Connector
Bin Control Sensor
4) CB 20VDC Output: Bin Control. Check that the BC green LED is on. If not, conrm
that BC yellow LED is not ashing or steady. If BC green or yellow LED is not on, check
for 20VDC at CB K6#1 (DBU) to CB K6 #3 (BR). See Fig. 3. If 20VDC is not present,
replace CB. If BC yellow LED is on or ashing, move ice away from BC lens. If no ice is
present, clean the lens with a warm, clean damp cloth. If BC green LED is not on, see
"II.D. Bin Control Check."
Fig. 2
Red positive test lead to
K5 pin closest to
K4 connector
Red Positive
Test Lead
Black Negative
Test Lead
Multimeter
5VDC
Float Switch (BK)
CB K8 Connector
Control Board K8 Connector