Scotsman MCM1062R - Manual (Page 25)

CONDITION DETERMINE CAUSE PROBABLE CORRECTION
Ice Machine does not run, it has
power to it, the high pressure
control is closed, the on/off switch is
set to ON (the compressor will not
operate until the liquid line valve
opens, but the pump should be
working if there is no ice in the bin). A. Listen for a ticking sound from
transducer. If no noise, go to C. If there is a
noise, check for a light on the board
(models built after 4/93). If there is a
light on, check relay contacts N.O.
and COM. The contacts should be
CLOSED. If closed, go to D. If not,
replace the board. If light is off, or
prior model, go to B.
B. Open bin door and twist
transducer 1/4 turn and pull out.
DO
NOT UNPLUG with power
connected
. Examine the
transducer, the inside must be
clean and dry.
If the inside of the transducer
(above screen) was wet, replace it.
Set bin level to FULL and aim at an
object about 1-3 feet away.
Machine should restart, if not go to
D.
C. Check power to bin level
control board.
Should be 12 volts from
transformer, if not replace
transformer. If there is power go to
D.
D. Disconnect electrical power
and test ice machine circuit by
attaching a jumper wire between bin
thermostat posts on circuit board
part no. 12-1912-01 (the circuit
board with the timer on it).
Reconnect power.
If machine does not start go back
to machine circuit. If machine
starts, disconnect electrical power,
remove jumper wire and reconnect
electrical power. Then go to E.
E. Transducer or ice level board
assembly defective. Replace transducer. Set bin level to
FULL and aim at an object about
1-3 feet away. Machine should
restart. If this does not repair unit,
replace the board.
Machine runs, makes ice, switches
on and off, but ice level cannot be
controlled. Ice level switch may be defective.
On boards with a light, check by
moving switch & watching light. Replace ice level switch
Machine runs, but will not shut off. Board relay stuck closed. Check
relay. If COM and N.O. are closed when
power is off, replace board. If open,
go to B above.
SERVICE DIAGNOSIS: Ice Level Control Circuit
PARTIAL VIEW OF
CIRCUIT BOARD
12-1912-01
BIN THERMOSTAT
PLUG - IN
RELAY
POSTS
MENTIONED
IN “D” ABOVE
TIMER
Electrical Shock Hazard
Can Cause Personal Injury.
Disconnect Power Before
Servicing.
Bin Thermostat Posts at Line
Voltage.
MCM1062R
October 1993
Page 25