Kodak TS800V TH5 02906/02920 Focus Find Failed Repair Case

Introduction

This field repair case summarizes a Kodak TS800V CTP focus acquisition failure on a TH5 laser head platform. The recorded messages were 02906 Coarse Focus Find Failed, Check Z Stage CRB and 02920 Not Enough Valid Data to Find Focus. The purpose of this article is to show a practical diagnostic path before assuming laser head failure.

Fault symptom

During startup or imaging preparation, the machine could not complete focus acquisition. Exposure stopped because the system did not obtain enough valid focus data from the CRB/focus scan process.

Error messages recorded

• 02906 Coarse Focus Find Failed
• Check Z Stage CRB
• 02920 Not Enough Valid Data to Find Focus

These messages point to a focus detection problem. They do not, by themselves, prove that the laser head must be replaced.

Initial diagnosis

The first diagnostic direction was to check the focus signal path and calibration state around the TH5 laser head, including CRB-related parameters, Z-stage focus behavior and whether the focus start routine could recover after adjustment.

Field inspection process

The engineer reviewed the fault sequence, checked focus-related parameters and adjusted the laser/CRB focus settings. After adjustment, the focus start routine was run again until the machine was able to find focus normally.

Probable cause

The available service record indicates a focus parameter or CRB focus signal condition rather than a confirmed hardware replacement case. The fault was resolved through parameter adjustment and focus acquisition recovery.

Repair solution

1. Confirmed the 02906 and 02920 focus fault sequence.
2. Checked CRB and focus-related settings.
3. Adjusted laser/CRB focus parameters.
4. Reran the focus start routine.
5. Verified that focus acquisition recovered and the fault no longer stopped exposure.

Final result

After adjustment, the machine found focus successfully and returned to normal operation. The result was based on the repair work order record: the focus start routine recovered and the issue was resolved.

Technical notes

For Kodak CTP focus faults, do not replace the laser head as the first step. Check CRB signal quality, Z-stage focus position, optics cleanliness and focus calibration data first. Error 02906 and 02920 are especially useful because they point to the focus scan process and valid focus-data acquisition.

Service CTA

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