BeamBalance.spt

When to run this script | Graphs | Data | Interpretation

This script executes the firmware command bbs balance and displays the beam profile in graphical format. The output of this script helps to show how much margin is left for future aging of the write laser and light valve.

When to run this script

Use this script to diagnose beam balance failures, banding and as part of preventative maintenance.
Note: Use bbsprofile.spt to diagnose stuck pixels.

Before interpreting the data:

1. Run contrvhv and select the correct hvtrim setting.
2. Run contrvbp and select the correct beamposition setting.
3. Make sure that maximumerror, beamslope, beamcurve and scorr settings are set correctly.

Graphs

• Sample 1: Example of a good beambalance result.
• Sample 2: Example of a bad beambalance result.

Interpretation

There should be a lot of buffer space between the minimum laser profile (full attenuation) and the balanced beam. This allows for aging of the laser and light valve.

• A flatter stroke table indicates that the beam is fairly easy to balance.
• The "Max Correction" field at the bottom of each graph indicates the largest stroke value used.
• The greatest possible stroke setting is 255. If the maximum correction is close to this value, the write laser beam may become difficult to balance.
• On the ratio graph result, if any point is at 0.8 or higher and you are experiencing image quality issues, the head may need to be replaced soon. This assumes that the hvtrim and beamposition has been optimized.

Data