390B4600

OKI B4600 Error 390: Step-by-Step Troubleshooting Guide

The OKI B4600 error 390 is a warning indicating a failure in the main motor synchronization. This issue prevents proper paper advancement and is often triggered by mechanical obstructions. Why is my OKI B4600 showing error 390 during a job? It is typically related to heavy workloads or internal toner dust affecting traction. The unit is a compact LED printer designed for small office environments.

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Common causes

  • 1Toner dust buildup affecting internal gears.
  • 2Debris or paper scraps blocking the feed path.
  • 3Mechanical wear of the main motor bearings.
  • 4Temporary motor sensor misalignment.

Solutions

Quick Diagnosis

The error 390 appears on the control panel with a flashing indicator. If the printer makes unusual grinding noises before stopping, a mechanical obstruction is the likely culprit.

Step-by-Step Solution

  1. Power off: Unplug the printer for at least 5 minutes.
  2. Check for jams: Remove the paper tray and check the feed area for obstructions.
  3. Internal cleaning: Gently clear toner residue from the gear area using compressed air.
  4. Reboot: Plug the unit back in and test.

Prevention and Maintenance

Keep the printer clean and avoid overloading the input tray to ensure longevity. Using genuine OEM toner is recommended to protect internal rollers from premature wear.

When to Call a Technician

If the error persists after a hard reset, or if you detect burning smells or persistent grinding sounds, professional repair is required.

Technical Specifications

  • Technology: LED Digital
  • Print speed: 27 ppm
  • Connectivity: USB 2.0 / Parallel
  • Input capacity: 250 sheets
  • Compatible consumables: B4600 Series Toner
  • Recommended use: Small Office
  • Official drivers / firmware

Steps to follow

  1. 1

    Power off and disconnect

    Turn off the printer and unplug it for 5 minutes to clear internal memory.

  2. 2

    Motor inspection

    Open the front cover and check for debris or paper jams near the main motor.

  3. 3

    System reboot

    Reconnect the device directly to a power outlet and restart the machine.

Frequently asked questions

Error 390 usually indicates a synchronization or mechanical failure of the printer's main motor.

It is a critical error that prevents printing, though it often clears with a basic power cycle.

Use original B4600 series toner cartridges for optimal performance.

Regular internal cleaning every 5,000 pages helps prevent sensor-related errors.