43856301TH Rev.3 175 /Oki Data CONFIDENTIAL 7. Troubleshooting and repair procedureCheck item Check work Action to be takenat NG(14-1-2) Check the system connectionCheck the systemconnection fromthe PU board to theoption tray board(V7Y PCB).Check that the cable between the PU boardoption connector to the option tray board isnormally connected.Correct theconnections.Square connectorconnecting theoption tray unit tothe printer.Check if any foreign material exists in theconnecting portion of the square connector.Remove theforeign material.Square connectorconnecting theoption tray unit tothe printer.Is the terminals of the square connectordamaged?Replace theconnector.(14-2-3) Check the control signals.Check the controlsignal that is outputfrom the PU boardto the option trayboard (V7Y PCB).Check the control signal that is output from thePU board option connector .Pin-5: TXD (PU 2nd)Pin-3: RXD (2nd PU)Replace the PUboard.7.5.2. (15) LED head cannot be recognized. (error code 131, 132, 133, 134)(15-1) Service call 131 to 134 (LED HEAD Missing)Check item Check work Action to be takenat NG(15-1-1) Check the system connectionConnectingcondition at the CUboard connectorand at the headconnector.Check the connecting condition of the FFC bythe visual inspection.Correct theconnectionto the normalconnectingcondition.Head FFC Remove the head FFC from the printer. Checkif any open-circuit or peeling-off of sheath hasoccurred or not throughout the cable.Replace thehead FFC or theCU board.Conduction of thefuse on the CUboard.Check that 5V appears across the capacitorsCP7 and CP8. (Refer to section 7.6.)Replace F504,F506 or replacethe CU board.
