Service Manual

23
C. Control Board Check
Before replacing CB 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.
Alarm Reset: If CB is in alarm (beeping), press the "ALARM RESET" button on CB
while CB is beeping. WARNING!Risk of electric shock. Care should be
taken not to touch live terminals. Once reset, the icemaker starts at the
1-minute ll cycle. For audible alarm information, see "III.B. LED Lights and
Audible Alarm Safeties."
1) 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, and 5are
cleaning adjustments and the settings are exible. For factory default settings, see
"III.C.1. Default Dip Switch Settings."
2) Move the control switch to the "ICE" position. If the red "POWER OK" LED is on, control
voltage is good, continue to step 3. If the "POWER OK" LED is off, check CT secondary
circuit. CT output is 10.5VAC at 115VAC primary input. If the secondary circuit has
proper voltage and the red LED is off, replace CB.
If the secondary circuit does not have proper voltage (10.5VAC), check CT primary
circuit. Check for 115VAC at control switch terminal #2 (BK) and control switch terminal
#3 (P) to neutral (W). If 115VAC is present at control switch terminal #2 (BK) and not
at control switch terminal #3 (P), replace control switch. If 115VAC is present at control
switch terminal #3 (P), check for 115VAC at HPS (BK) to neutral (W). If 115VAC is not
present, see "B.1. 3)b) HPS Diagnosis." If 115VAC is present check CT coil continuity.
Replace as needed. For additional checks, see "II.H.1. No Ice Production."
3) The "OUTPUT TEST" button provides a relay sequence test. Make sure the control
switch is in the "ICE" position, then press the "OUTPUT TEST" button. For the correct
lighting sequence, see the table below. Note that the order of the LEDs from the outer
edge of the control board is 1, 4, 3, 2. Components (e.g., compressor) cycle during the
test.
Following the test, the icemaker begins operation at the 1-minute ll cycle. If the LEDs
do not light as described above, replace CB.
4) To verify voltage output from CB to the components, slide the CB K1 connector out far
enough to allow multimeter lead contact. With the icemaker in the cycle to be tested,
check output voltage from the corresponding pin on CB K1 connector to a neutral
(W)wire. If output voltage is not found and the appropriate LED is on, replace CB.
5) Conrm BC communication and shutdown sequence: Move the control switch to the
"ICE" position. Once the ll cycle starts press and hold the BC actuator paddle. CB
shuts down the appliance after 15 sec.. If not, conrm BC status. See "II.D. Bin Control
Check." If BC checks ok, replace CB.
Legend: BC–bin control; CB–control board; CT–control transformer