Lexmark T522 Service Manual - Page 49

4520-xxx Duplex Unit Sub Error Codes Status byte 4 contains the most valuable information to help isolate a failing part or assembly in the duplex unit and is the only byte contained in the following table. Status Byte 4 00 01 02 03 04 05 06 07 08 0E 13 15 18 3D Explanation No duplex error. No problem was reported to the engine by the duplex system card. The leading edge of the sheet of paper never arrived at the input sensor. The duplex unit engine board never received media notification from the printer. The trailing edge of the sheet of paper never cleared the input sensor. The leading edge of the sheet of paper never arrived at the exit sensor. Note: This error is the most common due to the long length of the paper path between the input sensor and the exit sensor. The duplex logic thinks a sheet of paper is feeding to the duplex unit due to a sensor malfunction in the paper path when in fact the printer has not sent a command to send a sheet of paper to the duplex unit. The exit sensor detected a sheet of paper too early. The sheet of paper trailing edge did not clear the exit sensor in the desired length of time. The feed motor experienced a complete motor stall. The D.C. motor is under speed. The motor never reached the correct operating speed. There is paper left in the duplex unit. Paper was sensed during the homing operation during POST. There is paper left in the duplex unit. Paper was sensed during the D.C. motor diagnostic test during POST. The D.C. motor experienced an acceleration error. There is paper left in the duplex unit. Paper was sensed during IR clear during POST. Diagnostic Information 2-21