Service - Front Panel Components; Control & Autofill Board - Bunn Ultra NX Service & Repair Manual

Control Board and Auto-Fill Board
FIG. 1 CONTROL BOARD
Location:
The control board is located behind the front panel,
on the front of the chassis.
1. Remove the drip tray.
2. Loosen 2 screws on the underside of each side
panel. Lower the side panel while gently pulling
outward to remove panel.
3. Locate the single screw on the left and right
side securing the front panel to the frame.
4. Lower front of the machine, remove 1 screw
from underside the front panel.
5. The membrane switch will need to be discon-
nected before full removal of front panel. Gently
lower front panel and rest on the counter and
disconnect switch membrane from the wiring
harness.
Test Procedures:
1. Disconnect the dispenser from the power
source.
2. Remove the left and right side panels. Remove
the front panel and unplug membrane switch.
3. Connect the dispenser to the power source.
4. With a voltmeter, check the supply voltage
across J12-2 pin connector.
The indication must be: 24.0VDC
If voltage is present as described and the
dispenser does not operate, replace Control
Board.

SERVICE - FRONT PANEL COMPONENTS

If voltage is not present as described, refer to
the Wiring Diagram and check the dispenser
universal power supply and wiring harness.
Part Removal and Replacement:
1. Disconnect the dispenser from the power
source.
2. Remove 3 screws securing main control board
and set aside protective shield.
3. Disconnect 12pin, 14pin, 2pin and 6pin
connector from control board.
4. Disconnect the 12pin short wiring harness from
the control board.
5. On models with Auto-Fill (CFV OR LAF Models),
remove the auto-fill adapter board from the
backside of the main control board. See FIG. 2.
NOTE: The 12pin short wiring harness
and Auto-Fill board will connect onto the
replacement control board.
6. Reconnect all harness connectors onto the
control board.
7. Reinstall main control and protective shield
FIG. 2 AUTO-FILL BOARD
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