Bunn System III manual Digital Brewer Control Board And Display Dbc, Tion, Entry And Description

SERVICE (cont.)

DIGITAL BREWER CONTROL BOARD AND DISPLAY (DBC)

FIG. 12 DIGITAL CONTROL BOARD P1094.35

Location

The digital control board is located inside the upper front of the trunk on the component bracket.

The digital display is located in the upper center of the front of hood.

the following functions are set properly.

A)set refill probe delay (larger values add more delay time)

B)refill sensing probe ("no" means that there will be no automatic refill)

C)refill solenoid separate from brew solenoid (usually on gravity brewers) ("no" means that refill will occur automatically only when not brewing.

D)set refill resistance threshold (only necessary to change in pure water areas)(changing the set- ting to a value higher than 128 means the water will be more likely to create a full condition).

E)check wiring to refill solenoid

F)replace Digital Brewer Control Board

3.If the brewer will not heat then check the follow- ing.

A)test the main tank heater

B)check the main brew tank temperature setting

C)check dry plug-in prevention probe setting ("yes" means that there must be a dry plug-in prevention probe)

D)limit thermostat on top of the brewer tank

E)temporarily substitute a known working heater triac assembly

F)replace Digital Brewer Control Board

NOTE: Check the function list (supplied) for FUNC-

TION, ENTRY AND DESCRIPTION.

1.If display indicates a "FAULT" use the list below to troubleshoot the indicated fault.

FAULT 1 - main brew tank temperature probe is shorted

FAULT 2 - main brew tank temperature probe is open circuit

FAULT 3 - secondary water tank temperature probe is shorted (used only in two-tank system) FAULT 4 - secondary water tank temperature probe is open circuit (used only in two-tank sys- tem)

FAULT 5 - main DBC board is defective

FAULT 6 - water overflow protection switch is open circuit

FAULT 7 - dry plug-in condition (brewer is look- ing for connection between the water tank and the dry plug-in probe.

2.If the brewer will not refill then use the function list and test the refill solenoid and make sure that

4.If the brewer will not brew then use the function list and test the brew solenoid and make sure that the following functions are set properly.

A)set main brew tank temperature ( a setting that is lower than the ready lamp value can prevent brewing)

B)set main brew tank - ready lamp off temperature (a setting that is higher than the brew value can prevent brewing)

C)select brew lockout ("yes" requires the brewer ready lamp to be "ON" in order to brew)

D)replace Digital Brewer Control Board

5.If the temperature reading on the display is higher than 211˚F (99˚C), disconnect the two pin connec- tor (blue wire and tan wire) from the heater triac. If the heater remains on, the heater triac is defec- tive and must be replaced.

6.If the temperature on display varies by more than one degree while the brewer is at idle, select main

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