• Code: 503
• Description: 3rd tray lift malfunction (optional paper tray unit)
  The paper height sensor is not activated after the tray lift motor has been on for 13 seconds. If the main power switch is turned on when the paper is already at the feed height, the paper height position is detected again. At this time, the paper height sensor should de-activate within 5 seconds after the paper bottom plate starts to drop. If it does not deactivate within 5 s four times consecutively, the tray lift motor halts. After two attempts to re-set the paper tray, if this does not solve the problem, then this SC is displayed and tray control halts.
• Causes: • Tray lift motor defective or disconnected • Height sensor defective or disconnected

• Code: 504
• Description: 4th tray lift malfunction (optional paper tray unit)
  The paper height sensor is not activated after the tray lift motor has been on for 13 seconds. If the main power switch is turned on when the paper is already at the feed height, the paper height position is detected again. At this time, the paper height sensor should de-activate within 5 seconds after the paper bottom plate starts to drop. If it does not deactivate within 5 s four times consecutively, the tray lift motor halts. After two attempts to re-set the paper tray, if this does not solve the problem, then this SC is displayed and tray control halts.
• Causes: • Tray lift motor defective or disconnected • Height sensor defective or disconnected

• Code: 506
• Description: Paper tray unit main motor lock (optional paper tray)
  A main motor lock signal is detected for more than 50 ms during rotation.
• Causes: • Paper tray unit main motor defective • Paper tray unit main motor connection loose • Too much load on the drive mechanism

• Code: 507
• Description: LCT main motor lock (optional LCT)
  A main motor lock signal is detected for more than 50 ms during rotation.
• Causes: • LCT main motor defective • Paper tray unit main motor connection loose • Too much load on the drive mechanism

• Code: 510
• Description: LCT tray malfunction
  1) The LCT lift sensor does not activate for more than 18 seconds after the LCT lift motor turned on. 2) The LCT lower limit sensor does not activate for more than 18 seconds after the LCT lift motor turned on. 3) The LCT lift sensor is already activated when the LCT lift motor turns on. 4) After the paper end sensor is actuated while the tray is raising, the upper limit sensor is not actuated within 5 s. A message is displayed to remind the user to set the paper and tray control halts. Resetting the display is done by opening and closing the LCT door. 5) The 4) state has been detected 3 times in succession.
• Causes: • LCT lift motor defective or disconnected. • Upper limit sensor defective or disconnected • Pick-up solenoid defective or disconnected • Paper end sensor defective

• Code: 541
• Description: Fusing thermistor open
  The fusing temperature detected by the thermistor was below 7C (44.6F) for 5 seconds, or 2 seconds after reaching 45C (113F) the temperature does not reach an additional 15C (59F) after checking five times at 0.1 intervals.
• Causes: • Fusing thermistor disconnected • Fusing thermistor connector defective • Fusing thermistor damaged or warped • Fusing temperature œ15% less than the standard input voltage

• Code: 542
• Description: Fusing temperature warm-up error
  The fusing temperature does not reach the fusing standby temperature of 45C (113F) within 9 seconds [for the B003/B006 (35 cpm)]/14 seconds [for the B004/B007 (45 cpm)] after switching on the main power or closing the front cover, or 40 seconds after reaching 50C the fusing roller does not reach warm-up temperature.
• Causes: • Fusing lamp defective • Poor fusing unit connector • Thermistor warped or broken • Thermostat has tripped • BICU defective • Power supply board defective

• Code: 543
• Description: Fusing overheat error (software detection)
  A fusing temperature of over 230C (446F) is detected for 5 seconds by the fusing thermistors at the center or at either end of the fusing roller.
• Causes: • Power supply unit defective • I/O board (IOB) defective • BICU defective • Fusing thermistor defective