Hoshizaki DCM-271BAH Service Manual page 19

2. Opti-Serve Model
CB K8 connector pins #7 (R), #8 (Y) or (P), and #9 (BK): Before engaging the
water dispense OS sensor, check for the correct VDC from the locations given in
the "Disengaged" column in the table below. If the VDC is different than in the table,
replace CB. If the VDC is correct, engage the OS sensor. "WTRDP" LED turns on.
If not, confirm that the water dispense signal VDC matches the "Engaged" column
in the table below. If not, replace the OS sensor. If the VDC matches the "Engaged"
column below and the "WTRDP" LED does not turn on, replace CB.
Component
VDC Sensor Ground
Water Dispense Signal
5VDC Power Supply
Red positive
test lead to red
K4 connector
pin closest
to black K3
connector
5VDC CB K7 Connector
Pin # (Wire Color) To CB VDC Ground
#7 (R)
To
#8 (Y) or (P)
#9 (BK)
Multimeter
5VDC
Red Positive
Test Lead
Water Dispense (BK)
(5VDC power)
Water Dispense (Y) or (P)
(switch signal)
19
Red K4 pin closest
to black K3
Black Negative
Test Lead
Water Dispense (R)
(VDC GND)
Fig. 4
Disengaged Engaged
0VDC 0VDC
0VDC 5VDC
5VDC 5VDC
Control Board K7 Connector