390B840dn

OKI B840dn error 390: Causes and Troubleshooting

The OKI B840dn error 390 typically appears when the internal system detects a disruption in data flow. This message suggests that the printer controller cannot establish a stable connection with the network or the print server, requiring immediate troubleshooting. It is a common issue encountered in busy office environments with high network traffic.

1 views

Common causes

  • 1Synchronization failure between print server and logic board.
  • 2Physical damage to the network cable or port.
  • 3Duplicate or conflicting IP address on the local network.
  • 4Memory corruption during sudden power surges.

Solutions

Quick Diagnostics

The error 390 is identified when the LCD display alerts the user during a print task. If you are experiencing a communication failure in B840dn printer, check for the orange warning light on the operator panel.

Step-by-Step Solution

  1. Power Cycle: Turn off the printer and unplug it for one minute.
  2. Clear Buffer: Once restarted, clear any queued print jobs from the computer.
  3. Cable Inspection: Replace the Ethernet cable to verify that no physical damage is causing the error.
  4. Self-Test: Print a configuration sheet directly from the menu to test the internal controller independence.

Prevention and Maintenance

Use shielded Ethernet cables to reduce interference. Clean the contact points of the network port annually. Ensure the printer firmware is updated to the latest version to prevent bugs. For best quality, always use genuine high-capacity toner cartridges.

When to Call a Technician

If power cycling the printer and testing a new cable do not resolve the issue, the internal NIC (network interface card) or the main control board may be faulty.

Technical Data

  • Technology: Digital monochrome laser printer.
  • Speed: Up to 40 ppm.
  • Connectivity: 10/100/1000 Base-TX Ethernet.
  • Input Capacity: 530-sheet standard tray.
  • Consumables: B840 series high-capacity toner.
  • Recommended usage: High-demand office environment.
  • Official drivers / firmware

Steps to follow

  1. 1

    System Reset

    Power off the printer and disconnect both power and network cables for 60 seconds.

  2. 2

    Check Connections

    Inspect the Ethernet cable for signs of damage and ensure a secure fit at both ends.

  3. 3

    Verify IP Settings

    Access the panel and check that the IP address is static to avoid network conflicts.

Frequently asked questions

Error 390 usually indicates a communication breakdown between the logic board and the external network interface.

It is often a temporary glitch that resolves with a restart, though persistent errors may suggest hardware issues.

This unit uses the B840 series high-capacity toner cartridges designed for enterprise-level document production.

Keep your firmware updated and use high-quality surge protectors to prevent electrical interference with the mainboard.