55.xxLaserJet Pro M404dw

HP LaserJet Pro M404dw error 55.xx: Critical fix

The HP LaserJet Pro M404dw error 55.xx indicates a significant communication fault between the printer's main engine and the DC controller. This often happens after power surges or sudden brownouts. If your HP LaserJet Pro M404dw shows error 55.xx, the machine is failing its initialization sequence, effectively bricking the device until the communication link can be restored or the hardware logic is repaired.

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Common causes

  • 1DC Controller memory hardware failure.
  • 2Corrupted firmware data causing boot failures.
  • 3Surge damage affecting internal data buses.
  • 4Loose internal wiring to the printer engine assembly.

Solutions

Quick Diagnosis

If the machine hangs on the startup screen with the 55.xx code immediately upon power-up, you are likely looking at an engine controller communications error.

Step-by-Step Solution

  1. Disconnect power and all interface cables.
  2. Wait 5 minutes to clear internal memory.
  3. Reconnect only the power cord and boot.
  4. If the menu loads, perform a factory reset immediately.

Prevention and Maintenance

Use an industrial-grade UPS to buffer against power fluctuations. Keep the firmware updated as HP periodically releases patches for communication stability.

When to Call a Technician

If the printer consistently returns to the error state despite multiple hard resets, the logic board is likely faulty and requires a technician's inspection.

Device Specifications

  • Technology: Monochrome Laser
  • Engine Controller: Internal DC controller
  • Connectivity: LAN, USB, Wireless
  • Capacity: High performance
  • Consumable: HP 58 series
  • Usage: Corporate environments
  • Official Drivers / Firmware

Steps to follow

  1. 1

    Hard Reset

    Disconnect the printer from power for 5 full minutes to discharge capacitors.

  2. 2

    Check connections

    Unplug USB and network cables to eliminate external interference.

  3. 3

    Factory Reset

    If access is possible, restore settings to defaults via the printer menu.

Frequently asked questions

This indicates a communication failure between the DC controller and the printer engine.

A hard reset often fixes temporary data corruption, but a persistent 55.xx error usually points to a damaged system board.

It prevents the printer engine from initializing, making it impossible to print, regardless of the toner status.

Always use surge-protected power strips and ensure high-quality, shielded data cables.