If your HP LaserJet M1005 MFP is displaying the frustrating “Scanner Error 12”, you are dealing with a common optical or mechanical failure. This error prevents the printer from calibrating and starting up. Watching a detailed teardown is the best way to understand the internal layout before you begin.
Technical Video Walkthrough
Required Tools for the Repair
To perform a clean repair without damaging the plastic chassis, ensure you have the following professional tools:
- Precision Torx Screwdriver Set – Essential for HP hardware fasteners.
- Plastic Pry Tools (Spudgers) – To safely release the housing clips.
- Isopropyl Alcohol & Microfiber Cloth – For cleaning the calibration strip and glass.
Step-by-Step Module Replacement
1. Scanner CIS Module Replacement
The most common cause for Error 12 is a failing lamp or dirty mirrors inside the Scanner CIS (Contact Image Sensor) Unit. Instead of repairing the delicate internal optics, technicians prefer replacing the entire Scanner Head Module. This ensures the factory calibration remains intact.
2. Complete Scanner Assembly
If the motor or the internal gears are jammed, the most efficient solution is to install a new Scanner Assembly. This module includes the glass, housing, motor, and the scanning head itself. Replacing the whole unit is much faster and more reliable than trying to fix individual plastic gears.
3. Scanner Flat Cable Inspection
Communication errors often occur due to a worn-out Scanner Flat Cable. Constant movement can crack the internal copper traces. If you notice erratic head movement or “Error 12” appearing intermittently, replace the entire cable module. If you are experiencing other hardware issues like grabbing multiple sheets, see our guide on how to fix HP LaserJet 1010/1020 paper feed issues.
4. Final Testing with Toner Cartridge
Once the scanner is operational, you must verify print and copy quality. For the HP M1005, always use a high-quality Q2612A (12A) Toner Cartridge. For maintenance tips on this specific cartridge, refer to our ultimate guide on how to refill HP Q2612A (12A) toner.
Professional Advice: Before final assembly, clean the white calibration strip located under the scanner glass. If this strip has even a small smudge, the printer will trigger Error 12 again during the initial startup sequence.
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