Error Message:

IMAGE: PLL was not able to maintain drum motion tracking

Applies to:

• All

Service Information:

The drum position tracking system has been disrupted. It was tracking the drum motion during an image, but was unable to maintain that tracking for some reason.

It is possible for this error to be reported because of a system pressure problem. If the system pressure drops below the threshold for a short period of time, the drum will be stopped but the error may not be reported properly. As of drum module V1.32 (check the "list modules" command, if that command doesn't exist, your firmware is too old), then the statement "WARNING: Low air pressure detected!" will be displayed a few seconds prior to the error being reported. If that message was displayed, then the system pressure should be checked. Make sure the supply has enough volume, and also check for other devices using the same air line.

The drum encoder disk should be cleaned, carefully following the procedure in the Service Manual. The drum belt tension should also be checked.

The drum tracking can be disrupted by external vibration, such as heavy machinery nearby. This possible cause should be investigated.

If none of the above seem to be the cause, the following can be tried. The order in which they are attemted is arbitrary:

1. swap the MPE
2. re-align the drum encoder. This procedure requires an oscilloscope and training.
3. swap the drum motor and or driver. Refer to engine integrators for advice.

There have been cases where warped or cracked drum encoders have been found. This disk can be inspected with a microscope, and as a last resort, replaced.

Operator Action:

Record error message and contact Creo Service

Cause:

• Dirty drum encoder.
• Improperly adjusted drum belt tension.
• External vibration.
• Faulty MPE.
• "Mismatched" drum motor and driver.
• Misaligned or faulty drum encoder.
• Warped or cracked drum encoder disk.
• System pressure problems.

See Also:

• Other: Troubleshooting information