390B401d

OKI B401d error 390: Toner detected failure

OKI B401d error 390 signifies a sensor issue regarding the detection of the toner cartridge. Why is my OKI B401d showing error 390? This often results from a misaligned cartridge or contaminated chip contacts. This is a common notification that users encounter when swapping supplies, and it is usually resolved by simple physical adjustment.

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Common causes

  • 1Improper installation of the toner assembly.
  • 2Dirty chip contact points on the toner cartridge.
  • 3Incompatible or faulty third-party toner chip.
  • 4Accumulation of toner dust on internal sensing components.

Solutions

Diagnóstico rápido

When the B401d displays error 390, the printer is unable to communicate with the toner chip. Confirm the cartridge is fully inserted; the error often vanishes once the physical connection is properly established.

Solución paso a paso

  1. Open: Open the printer front cover.
  2. Remove: Take out the toner and drum assembly.
  3. Inspect: Check for any plastic protective film left on the toner.
  4. Reseat: Reinsert the unit firmly until you hear the engagement click.

Prevención y mantenimiento

Keep the internal housing free of excess toner dust using a small dry brush. Only use official OKI consumables to ensure the chip data matches the machine requirements perfectly. Store spare toners in a cool, dry place to prevent moisture damage.

Cuándo llamar a un técnico

If replacing the toner with a new genuine one does not clear the error, the internal sensor housing might have failed. Contact technical support to avoid causing further damage to the unit.

Ficha técnica del equipo

  • Technology: Monochrome LED.
  • Resolution: 2400 x 600 dpi.
  • Connectivity: USB 2.0.
  • Compatible Consumable: B401 / MB441 Series (44992401).
  • Duty Cycle: 30,000 pages.
  • Official drivers / firmware

Steps to follow

  1. 1

    Open cover

    Carefully open the front cover to access the toner and drum assembly.

  2. 2

    Reseat toner

    Remove and firmly reinsert the toner cartridge until it clicks.

  3. 3

    Clean contacts

    Wipe the gold chip contacts with a soft, dry lint-free cloth.

Frequently asked questions

This code means the printer's sensor cannot read or verify the toner cartridge chip.

No, it's just a communication alert with the consumable, but it must be resolved to print again.

Try reseating it first; if the error persists, the cartridge chip may be faulty.

Always use genuine OKI consumables and keep the internal carriage clean from toner dust.

OKI B401d error 390: Toner detected failure | Vimazdev