• Code: 390
• Description: TD sensor error: Test value abnormal
  The TD sensor output voltage is less than 0.5V or more than 5.0V after 10 consecutive times during copying.
• Causes: • TD sensor defective • TD sensor not connected or connector damaged • Poor connection between the TD sensor and the I/O board (IOB) • I/O board (IOB) defective • Toner supply defective

• Code: 391
• Description: TD sensor error: Auto adjust error
  During automatic adjustment of the TD sensor, output voltage is less than 1.8V or more than 4.8V during TD sensor initial setting.
• Causes: • TD sensor abnormal • TD sensor disconnected • Poor TD sensor connection • I/O board (IOB) defective • Toner supply defective

• Code: 395
• Description: Development output abnormal
  A development bias leak signal is detected. High voltage output to the development unit exceeded the upper limit (65%) for 60 ms.
• Causes: • High voltage supply board defective • Poor connection at the development bias terminal • Poor connection at the high voltage supply board

• Code: 401
• Description: Transfer roller leak detected
  A transfer roller current leak signal is detected.
• Causes: • High voltage supply board defective • Poor cable connection or defective cable • Transfer connector defective

• Code: 402
• Description: Transfer roller open error
  The transfer roller current feedback signal is not detected.
• Causes: • High voltage supply board defective • Transfer connector cable defective • Transfer connector defective • Poor PCU connection

• Code: 403
• Description: Transfer belt position sensor error
  The transfer belt position sensor does not activate even if the transfer belt contact clutch has been switched on twice and rotated once.
• Causes: • Main motor/drive malfunction • Transfer belt contact clutch defective • Transfer belt position sensor defective • Harness disconnected

• Code: 405
• Description: Transfer belt error
  The transfer belt does not move away from the drum during ID sensor pattern checking.
• Causes: • Main motor/drive malfunction • Transfer belt position sensor defective • Poor transfer belt position sensor connection • Transfer belt contact clutch defective

• Code: 440
• Description: Main motor lock
  A main motor lock signal is not detected within 2 seconds after the main motor turns on.
• Causes: • Too much load on the drive mechanism • Main motor defective