Bunn CDBC-DV Operating & Service Manual Download Page 11

Page 11

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 personnel.

All electronic components have 120 volt ac and 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.

29707 112801

Summary of Contents for CDBC-DV

Page 1: ...A MOD EL S N VOL TS A C AMP WAT TS PHA SE WIRE HER TZ COV ERE D UND ER ONE OR MOR EOF THE FOL LOW ING PAT ENT S ONE OR MOR E OTH ER PAT ENT S MAY BE PEN DING C A U T IO N W A R M E R S A N D S U R F A...

Page 2: ...3227 2 if requested by BUNN shipping the defective equipment prepaid to an authorized BUNN service location and 3 receiving prior authorization from BUNN that the defective equipment is under warrant...

Page 3: ...40 V 12 13 7 A 2440 3230 W 1PH 3 Wire 60HZ 29710 0004 DV models only APS BREWERS When re wiring the machine for operation on 120 208V or 120 240V the replacement Power Supply Cord must be UL Listed Fl...

Page 4: ...PH 3 Wire 60HZ Optional Field Wiring 120 208 240 V 13 0 15 0 A 2680 3550 W 1PH 3 Wire 60HZ 29710 0008 DV models only CDBC LPTC DV BREWERS 29710 0007 DV models only NO WARMER BREWERS 29707 080503 12364...

Page 5: ...rough the rear of the brewer 7 Using the above diagrams connect the desired electrical service to the field wiring terminal block 8 Ifre wiringthemachineforoperationon120 208or120 240voltswithaPowerSu...

Page 6: ...e field wiring terminal block and remove the top cover of the brewer to verify the tank heater terminal block connections 8 The electrical service connections at the field wiring terminal block must a...

Page 7: ...W switch 6 When brewing is completed simply discard the grounds and filter CLEANING 1 The use of a damp cloth rinsed in any mild non abrasive liquid detergent is recommended for cleaning all surfaces...

Page 8: ...position because the tank will not refill BREW SWITCH Momentarily pressing and releasing the switch starts a brew cycle when the ON OFF indicator is glowing NOTE The ON OFF indicator must be glowing t...

Page 9: ...ason the brew can t begin To change the condition of the brew lockout press and hold the HIDDEN switch beneath the and momentarily press the BREW switch Adjusting Automatic Warmer Shut Off The brewer...

Page 10: ...thesolenoidclickon and offthreetimes approximately5seconds thenreleasethe BREW switch Momentarily press and release the BREW switch once for each ounce approximate of water to be added to the prior se...

Page 11: ...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 WARNIN...

Page 12: ...t the brewer from the power source and remove wires from refill valve coil Check for con tinuity across the terminals of the solenoid coil If continuity is not present replace the refill valve See pag...

Page 13: ...etemperatureprobe up about an inch from the grom met Check for continuity from the outside surface of the temperature probe and pin 4 of the plug conti nuity should be present Connect the J3 plug to t...

Page 14: ...nuity from the outside surface of the temperature probe and pin 4 of the plug continuity should be present Connect the J3 plug to the control board and proceed to step 4 Remove the probe from the grom...

Page 15: ...the power source Check for continuity between the white terminal of the terminal block or red terminal on 208 240volt models and the black wire on the relay on the control board Toggle Switch must be...

Page 16: ...ectanohmmetertopins3and4of theJ3connector At60 F 16 C the readingshouldbe15 3k 2kOHMS at 70 F 21 C the reading should be 11 8k 2k OHMS and at 80 F 27 C the reading should be 9 3k 2k OHMS If the probe...

Page 17: ...ermi nals at the terminal block The indicator lamp must be lit Allow brewer to heat until ready lamp is lit or disable the brew lock out feature See page 8 Press ON OFF switch indicator must be lit Br...

Page 18: ...uity is present the valve may be stuck closed Set up brewer according to instruc tionsinsection Adjustments Brew Volumes Seepage8 Usingastop watch or second hand time the length of the brew cycle Reco...

Page 19: ...six holestainlesssteelsprayhead must be used for proper extraction Place an empty brew funnel on an empty decanter beneath the spray head Initiate brew cycle and check the water temperature immediatel...

Page 20: ...nd the bed of grounds leveled by shaking gen tly Disconnect the brewer from the power source Remove the warmer plate and turn upside down to ex posethewarmerterminals Remove the two wires Check for co...

Page 21: ...lt Water pressure Is water shut OFF Level probe dry for 7 minutes after fill valve is energized Level probe wiring Temperature probe wiring Fill valve wiring function strainer 3 Low Water Temperature...

Page 22: ...istance in determining the cause of any problem WARNING Inspection testing and repair of electri cal equipment should be performed only by qualified service personnel The brewer should be unplugged wh...

Page 23: ...ector and the 4 pin connector from the main wiring harness 3 Disconnect the 11 pin connector from the control panel 4 Remove the four 6 screws and four nylon wash ers and the two 4 40 screws securing...

Page 24: ...he two 4 40 screws securing the control board to the end cap assembly and set aside 3 Gently pry the switch panel from the end cap assembly 4 Removeanyadhesivethatremainsontheendcap 5 Removetheadhesiv...

Page 25: ...nse valve coil terminals Connect the brewer to the power source Brewer temperature lockout must be disabled Place ON OFF Switch in the ON position Press and release the brew switch The indication must...

Page 26: ...ntinuity is present as described the limit thermo stat is operating properly If continuity is not present as described replace the limit thermostat P1800 P1854 SERVICE cont BLU from Control Board BLK...

Page 27: ...n must be 240 volts ac 5 Disconnect the brewer from the power source If voltage is present as described proceed to 6 If voltage is not present as described refer to the Wiring Diagrams and check wirin...

Page 28: ...r 240V A C WHITE NEUTRAL L1 BLACK L2 RED L2 RED L2 RED 1800W 120V 1425W 120V 2390W 120 208V or 3180W 120 240V 120V A C WHITE NEUTRAL L1 BLACK 120V A C WHITE NEUTRAL L1 BLACK 1800W 1425W B L K B L U W...

Page 29: ...he selector switch in the 120V position check for continuity between the two empty terminals of the switch 7 Disconnect the white violet wire from the selector switch With the selector switch in the 1...

Page 30: ...position press start switch and listen carefully in the vicinity of the refill valve for a clicking sound as the coil magnet attracts 7 Disconnect the brewer from the power source If the sound is hear...

Page 31: ...s and check brewer wiring harness 4 Check the continuity across the two terminals on the warmer element Ifcontinuityispresentasdescribed reconnectthetwo wires to the warmer element If continuity is no...

Page 32: ...urce 2 Remove the cap from the fuse holder and remove the fuse 3 With an ohmmeter check for continuity through the fuse If continuity is present as described reinstall the fuse the fuse is operating p...

Page 33: ...eter check for continuity across the thermal fuse terminals If continuity is present as described the thermal fuse is operating properly If continuity is not present as described replace the thermal f...

Page 34: ...20V AC 2 WIRE 120 208V AC 3 WIRE 120 240V AC 3 WIRE SINGLE PHASE YEL WHI VIO WHI VIO WHI VIO VIO BLK WHI YEL YEL W H I W H I CONTROL PANEL ASSY J2 1 J2 6 J2 11 BREW SW STATIC SHIELD ON OFF SW HIDDEN S...

Page 35: ...5 J1 10 C O N T R O L P C B O A R D COM N O BLK BLK BLK 14 BLK 14 BLK 14 BLK WHI GRN WHI GRN WHI BLU WHI BLU COUNTER OPTIONAL 120V AC 2 WIRE 120 208V AC 3 WIRE 120 240V AC 3 WIRE SINGLE PHASE BLK CONT...

Page 36: ...E 120 208V AC 3 WIRE 120 240V AC 3 WIRE SINGLE PHASE YEL WHI VIO WHI VIO WHI VIO VIO BLK WHI YEL YEL W H I W H I CONTROL PANEL ASSY J2 1 J2 6 J2 11 BREW SW STATIC SHIELD ON OFF SW HIDDEN SW LT FRNT SW...

Page 37: ...O L P C B O A R D COM N O BLK BLK BLK BLK 14 BLK WHI GRN WHI GRN WHI BLU WHI BLU COUNTER OPTIONAL 120V AC 2 WIRE 120 208V AC 3 WIRE 120 240V AC 3 WIRE SINGLE PHASE BLK WHI CONTROL PANEL ASSY J2 1 J2...

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