Bunn System III manual DIGITAL BREWER CONTROL BOARD AND DISPLAY DBC cont, SERVICE cont

SERVICE (cont.)

DIGITAL BREWER CONTROL BOARD AND DISPLAY (DBC) (cont.)

heater relay or triac. ("0" means the temperature will be allowed to vary by the value in "set relay temperature difference")

7.If you cannot access the DBC with the password you have entered, the password has been changed. If you know what the brew settings are you can "reset" the memory back to the way it left the factory, which is "0". This is accomplished by disconnecting the brewer from the power source, pressing the plus (+) and minus (-) buttons simul- taneously and holding them in this position then connecting the brewer to the power source. Con- tinue pressing the buttons until the display shows numbers counting upward rapidly. If this does not occur press the plus (+) and minus(-) firmly and repeat the procedure. The brew values can now be set to your desired value.

8.If the brew volume does not match the pro- grammed value then use the following list to correct the error.

A)The coffee grounds naturally absorb some of the brew water; typically between one and two ounces of water per ounce of coffee (depending on the grind).

B)The DBC calculates the amount of time the brew solenoid must stay on to dispense the programmed brew volume. It uses the sprayhead constant to determine the rate of dispense. The sprayhead rate can be measured by capturing the water coming out of the sprayhead for 60 seconds. This value (in gallons per minute) can be entered into memory.

C)The last reason can be the brew by-pass. If you are using brew by-pass then the amount that comes out of the by-pass must be subtracted from the total desired volume to get the programmed brew volume.

9.If your DBC display is blank, you should check the following.

A)Make sure brewer is connected to the power source.

B)Make sure connectors that go between the main DBC and the DBC display are plugged into their appropriate locations.

C)Restart the DBC program by disconnecting

brewer from the power source, wait 15 seconds and reconnect the brewer to the power source.

D)If these do not remedy the problem, replace Digital Brewer Control Board

10.If water is running out from the base of the brewer check the following:

A)If the display shows temperature or FAULT 6 , disconnect the brewer from the power source. If water continues to flow out of the base of the brewer there may be an obstruction in the refill solenoid valve. Refer to Refill Solenoid Valve ser- vice procedures.

B)With the brewer disconnected from the power source, remove panels as necessary, dry inside of brewer as needed, and reinstall panels on brewer.

C)Reconnect brewer to the power supply. If water continues to flow out of the base, the Digital Brewer Control Board is defective and must be replaced.

Removal and Replacement:

DBC Control Board

1.Disconnect the brewer from the power source.

2.Disconnect all wires from the control board.

3.Remove the two #8-32 keps nuts securing control board to component bracket inside the trunk.

4.Remove control board and discard,

5.Install new control board on the component bracket using two #8-32 keps nuts.

6.Reconnect the multi-pin plugs to the control board.

DBC Display Assembly:

1.Disconnect the display assembly cord from the display assembly.

2.Remove the two #6-32 locking screws securing the display assembly to the display assembly mounting bracket behind the front of the hood.

3.Remove display assembly from the front of the hood and discard.

4.Install new display assembly on the front of the hood using two #6-32 locking screws to secure it to the display assembly mounting bracket.

5.Reconnect the display assembly cord to the dis- play assembly.

NOTE: If necessary recalibrate the values of the DBC using the FUNCTION LIST (supplied).

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