
Ask the customer to send a sample printout via fax or email.

Identify the cause of the issue using the Print Defects Guide from the Help Menu.
To do this, navigate to: Menu Button > Help >Print Defects Guide. Click here to see a sample.

Measure the defect's interval. Refer to the sample printouts in the customer-level section of this document to see how the measurement was done.
Note: The fuser repeating defect distance is 94.25mm ‑ 95.2mm (3.71" ‑ 3.75").

Check the Supply Level of the Imaging Unit by printing Device Statistics.
To do this, navigate to: Menu Button > Reports > Device Statistics.
- If the Supply level is low, tell the customer to purchase a replacement Imaging Unit as it may already be worn out.
- If the Supply level is still sufficient, proceed with the next step.

Check whether the customer has a different Imaging Unit in order to try swapping it with the original as a test.
- If the defect clears when using a different Imaging Unit, this replacement test would prove the original is defective.
- If the customer does not have a replacement unit to try this with, however, send a replacement Imaging Unit as the original one might be defective.
- MS/MX31x/41x/51x/61x – 50F0Z00 – WW Return MS/MX31x/41x/51x/61x Imaging Unit
- MS/MX71x/81x - 52D0Z00 – WW Return MS/MX71x/81x Imaging Unit

If the defect persists even after replacing the Imaging Unit, replace the Fuser.
Note: Do NOT send out a fuser unless a replacement Imaging Unit did not resolve the issue
- Fuser – Pick an appropriate fuser based on media size and electrical requirements for the region.

Should there be additional concerns or questions, contact the next level of support for further diagnosis.