Kodak CTP Laser Head Repair - Coarse Focus Find Failed

Introduction

This document details the diagnosis and repair process for a Kodak Trendsetter CTP system exhibiting a ‘Coarse Focus Find Failed Direct Publish’ fault code. This repair addresses common issues affecting laser head performance and ultimately enables consistent image quality.

Machine Information

• Machine Model: Kodak Trendsetter 800
• Machine Series: Trendsetter
• Laser Head Model: TH5
• Fault Code: Coarse Focus Find Failed Direct Publish

Fault Symptom

The machine failed during startup self-check and could not complete the focus scan, preventing proper image transfer.

Initial Diagnosis

Upon receiving the report of a ‘Coarse Focus Find Failed Direct Publish’ error, our initial assessment focuses on verifying the system self-check results, confirming the fault code, and checking for obvious physical obstructions.

Inspection Process

1. Optical Path Inspection: Thorough visual inspection of the laser head optical path for dust, debris, or smudges.
2. CRB Signal Analysis: Measurement and analysis of the CRB (Compensation Raster Beam) signal strength and integrity using diagnostic tools.
3. Z Focus Position Verification: Manual and automated verification of the Z focus position utilizing the Trendsetter’s built-in calibration routines.
4. Laser Head Mechanical Inspection: Assessment of laser head movement and operation for any mechanical binding or obstruction.

Root Cause

Weak CRB signal caused by optical contamination (dust, fingerprints) on the optical path and a corresponding deviation in the Z focus position, hindering accurate laser alignment.

Repair Solution

1. Cleaned the optical path thoroughly with appropriate cleaning solutions and lint-free cloths.
2. Checked and optimized the CRB signal strength, implementing corrective adjustments if necessary.
3. Adjusted the Z focus position according to the Trendsetter’s calibration protocols, ensuring proper laser alignment with the target.
4. Reran the edge find and focus scan to verify the corrected operation.

Final Test Result

Following the repair solution, the Trendsetter CTP system successfully completed the edge find and focus scan without error, demonstrating restored laser head functionality and accurate image transfer.

Technical Notes

• Regular cleaning of the optical path is crucial for maintaining laser head performance.
• Variations in CRB signal strength can be affected by environmental factors and system settings.
• Accurate Z focus calibration is fundamental to achieving optimal image quality.

Related Kodak CTP Repair Services

DTP TECH provides Kodak CTP laser head repair, LVD troubleshooting, focus calibration, CRB signal diagnosis and remote technical support for used Kodak CTP systems.