41956001TH Rev.6 111 /Oki Data CONFIDENTIAL5.5.2 Preparing for troubleshooting(1) Operator panel displayProblems that are generated in this device are indicated in the LCD.Apply proper measures according to the message displayed in the LCD.Note: When changing the engine board (K7N PWB), remove the EEPROM chip from the oldboard and install it on the newly replaced board(2) CU assembly troubleshootingNo operationIs an error message displayed?YES Perform according to the error message.•No Is black displayed in the top and bottom lines of the operator panel LCD?•No Check the power voltage 3.3V, 5V3.3V is open space 2 pin for JTAGW5V is 2, 3 pins for open space HD5V.No Replace the power supply.•YES Check the PU board and operator panel board.•YES Is ROM DIMM A set properly?No Set a program DIMM to ROM DIMM A properly.If the error is not recovered, replace the CU board.•YES Replace the CU board.Remove EEPROM from the old board and install it on the new board.No.123456ProblemThe printer does not function properly after power ON.Jam errorFeed jam (1st tray)Feed jam (multipurpose tray)Path jamExit jamDuplex jamPaper size errorI/D up/down errorFuser unit errorFan motor errorFlow Chart No.12-12-22-32-42-53456
