Bunn Fast Cup Series Service & Repair Manual page 9

TROUBLESHOOTING
MACHINE MESSAGES, SYMP-
TOMS and/or ACTIVE NOTICES
Symptoms
Entire Home Screen "Grayed Out"
13. Touch Screen Not Illuminated or ON
14. Irregular or Low Flow Out of Dispense
Nozzle and/or Brew Pump Operating
Unusually Louder During Brew Dispense
Note: Pump motor decreases or in-
creases RPM to maintain flow rate
PROBABLE CAUSE
c. Tank Temperature Too Low
d. Open or Failed Door Interrupt Switch
e. See Information Bar and/or Active
Notice icon for additional causes
a. Main power supply
b. Machine On/Off Switch
c. Universal Power Supply 24.0VDC
d. Input/Output Board
e. Circuit Breaker
a. Upper piston filter screen com-
promised, coffee grounds escaping
chamber
b. An obstruction in the coffee dispense
path.
9
REMEDY
c. Brew Lockout feature enabled. Found
under Machine Settings icon/Tempera-
ture tab
d. Close the open door. The switch opera-
tion "closed/open" can be viewed under
the Service icon/Sensor tab
e. Troubleshoot and/or test components
relating to the additional cause
a. Check outlet for power
b. Turn ON main power switch
c. Test machine On/Off switch
c. 24.0VDC must be present on the output
side of the power supply.
d. 24.0VDC must be present across the
Input/Output control board connector
terminals J11-1 (+) and J11-7 (-)
e. I f Input/Output & High Voltage circuit
boards are powered (LED's On), but
display is not powered, reset and/or test
circuit breaker.
a. Replace upper piston screen
b. Clean or replace upper piston screen,
dispense solenoid valve.
Unscrew dispense nozzle, remove and
clean internal parts.
Continued >