head-openPC42t Plus

Honeywell PC42t Plus error Head Open: Troubleshooting

The Honeywell PC42t Plus error Head Open appears when the safety sensor does not detect the thermal print head as completely closed. This minor fault prevents any print cycles until the mechanism is properly adjusted or the sensor is cleaned of debris. This is a very robust desktop label printer for logistics and commerce.

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Common causes

  • 1Incomplete closure of the top cover mechanism
  • 2Obstructing ribbon scraps or adhesive on the sensor
  • 3Failed lid closure spring
  • 4Dirt buildup on the safety switch

Solutions

Quick Diagnostics

The Head Open error is a protection mechanism to prevent the print head from printing without sufficient pressure on the ribbon or label. If the display shows this message even with the lid closed, it signals that the sensor is stuck or the pressure spring has weakened.

Step-by-step Solution

  1. Open the top cover by pressing the side buttons.
  2. Verify that there are no jammed labels or ribbon scraps obstructing the closure.
  3. Inspect the small sensor on the printer frame (sometimes a small tab).
  4. Close the lid with constant force until you hear the side latch engage.
  5. Restart the device using the rear switch.

Prevention and Maintenance

Regularly clean the thermal print head with a specific cleaning pen or isopropyl alcohol (99%). Avoid using low-quality labels that leave adhesive residue on the platen roller, which can force the mechanism's closure.

When to Call a Technician

If after performing the mechanical closure the Head Open error remains constant, the proximity sensor (internal switch) may be damaged and requires electrical repair.

Technical Data Sheet

  • Technology: Thermal Transfer / Direct Thermal
  • Resolution: 203 dpi
  • Connectivity: USB, Ethernet, Serial
  • Max Width: 104 mm
  • Compatible Consumables: Ribbon rolls (wax, resin, wax/resin) 1/2" or 1" core
  • Recommended Use: Shipping labels, retail, and pharmacy
  • Drivers / official firmware

Steps to follow

  1. 1

    Opening

    Press the side buttons to fully open the print head cover.

  2. 2

    Cleaning

    Clean the position sensors with a cotton swab dipped in isopropyl alcohol to remove buildup.

  3. 3

    Firm closure

    Close the cover pressing firmly until you hear the 'click' of the locking mechanism.

Frequently asked questions

This error occurs when the security sensor fails to detect the thermal print head completely closed or there is a mechanism blockage.

It is not serious, but it stops label production; it is almost always solved by verifying the print head adjustment.

It uses standard 1/2 inch (or 1 inch depending on version) thermal transfer ribbons.

Light cleaning with every roll change is recommended to prevent burnt adhesive on the sensor.