Left & Right Torque Sensor Board - Bunn Ultra NX Service & Repair Manual

Left and Right Torque Sensor Board
FIG. 13 CBA POSITION/TORQUE SENSOR
Location:
The torque sensor circuit board is located on the
upper rear of the cooling drum.
NOTE: The above pictorial has one auger motor
hidden to show location of the position sensor.
Rear Cover Removal:
1. Remove 4 screws securing rear cover.
2. Grab cover and pull away from machine.
Test Procedures:
NOTE: Best to perform Part Removal Instruction
steps 1 thru 6 to access circuit board connector for
testing procedure.
1. Place black meter lead at J1-3 (common)
and red lead at J1-1 (signal). Set meter to
10 - 20volts DC scale. Turn on power switch.
DO NOT TURN ON AUGERS!
2. Using a strip of paper, momentarily block the
light path between red LED and white photo
transistor. If the meter displays 5vdc when
blocked and 0v when unblocked, then the
Torque Sensor is good. If there is no 5vdc
reading, verify that both red and white sensors
are clean. See FIG. 14.
3. If there is still no 5vdc reading when blocked,
place the red meter lead at J1-2 and verify that
there is 4.5vdc supplied to Torque Sensor. If
there is no 5vdc supplied, check wiring between
control board and Torque Sensor. If wiring is
ok, then replace the main control board.
SERVICE - REAR COVER COMPONENTS
1
J 1
FIG. 14 TORQUE SENSOR BOARD
36
1. Left Signal (WHI/GRY)
1. Right Signal (WHI/GRN)
2. (+) 5vdc (BLU)
3. (-) common (WHI/BLK)
L.E.D.
PHOTO TRANSISTOR
TERMINALS
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