Bunn ICB/TWIN, ITB/ITCB manual Troubleshooting, Control Boards

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TROUBLESHOOTING

A troubleshooting guide is provided to suggest probable causes and remedies for the most likely problems encountered. If the problem remains after exhausting the troubleshooting steps, contact the Bunn-O-Matic Technical Service Department.

•Inspection, testing, and repair of electrical equipment should be performed only by qualified service person- nel.

•All electronic components have ac line voltage and some have low voltage dc potential on their terminals. Shorting of terminals or the application of external voltages may result in board failure.

•Intermittent operation of electronic circuit boards is unlikely. Board failure will normally be permanent. If an intermittent condition is encountered, the cause will likely be a switch contact or a loose connection at a terminal or crimp.

•Solenoid removal requires interrupting the water supply to the valve. Damage may result if solenoids are energized for more than ten minutes without a supply of water.

•The use of two wrenches is recommended whenever plumbing fittings are tightened or loosened. This will help to avoid twists and kinks in the tubing.

•Make certain that all plumbing connections are sealed and electrical connections tight and isolated.

•This brewer is heated at all times. Keep away from combustibles.

WARNING

•Exercise extreme caution when servicing electrical equipment.

•Unplug the brewer when servicing, except when electrical tests are specified.

•Follow recommended service procedures.

•Replace all protective shields or safety notices.

Before troubleshooting this brewer, check for the following:

Control Boards

1.Make sure ribbon cable is properly attached to the control board (ALL PINS INSERTED INTO PLUG).

2.Make sure there is a nylon insulating washer under each screw head that holds the control board to the plastic front end cap. This is important for proper operation.

3.Make sure before servicing brewer that voltage is present at control board.

4.Press any warmer switch or observe if any indicator lights are glowing on the control panel. If so, proceed with testing. If not, check for voltage across pins 1 & 2 of the ten pin J1 connector (black and white wires). If voltage is present, replace the control board. If voltage is not present, check wiring and voltage across terminal block (black and white). Correct the problem and retest before proceeding with testing.

NOTE: In the event of board replacement, technician will need to re-program customer's settings and/or recipes, as well as re-calibrate the temperature probe in program level 3 and re-enter the serial number in level 4.

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42461 0911809

 

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Contents ITB/ITCB ICB/TWIN BUNN-O-MATIC Commercial Product Warranty Introduction Troubleshooting Control BoardsTroubleshooting Refill Circuit ProblemProbable Cause RemedyHeating Circuit Problem Probable Cause Remedy Brewing Circuit Problem Probable Cause Remedy Troubleshooting Brewing Circuit Problem Probable Cause RemedyDiagnostics Message Probable Cause RemedyComponent Access ICB Component AccessControl Board Membrane Switch Membrane Switch ContinuityEarly Brew Valve Exploded ViewBrew Valve Late Models Late Model Brew ValveDisassembly Refill ValvesRefill Valves Early ICB Early ItcbTank Heaters ICB Twin Tank HeatersLimit Thermostat Limit ThermostatsTemperature Probe Testing Temperature ProbeCalibration Calibrate Temp ProbeVoltage Selector Switch Test ProcedurePower Switch Test Procedure Removal and ReplacementSchematic Wiring Diagram iTCBA, iTCBB Schematic Wiring Diagram With Factory Sweetener Schematic Wiring Diagram ICB-DV Schematic Wiring Diagram ICB Twin Schematic Wiring Diagram iCBA, iCBB Schematic Wiring Diagram ICB Twin 230V Chassis Ground Term Schematic Wiring Diagram ITB
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