Service manual

Page 10
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qualiedserviceperson-
nel.
• 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ttings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specied.
  • Followrecommendedserviceprocedures.
  • Replaceallprotectiveshieldsorsafetynotices.
Before troubleshooting this brewer, check for the following:
A. Control Boards
Make sure ribbon cable is properly attached to the control board (ALL PINS INSERTED INTO PLUG).
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.
B. Make sure before servicing brewer that voltage is present at control board.
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(s) (black and white). Correct the problem and retest before proceeding with testing.
36672 030104