Model 78xx Series.
Problem: Document handler is calibrated wrongly causing documents to be wrongly positioned on the page compared to original.
Solution: There is an automatic calibration routine in diagnostics>adjustments> dc608 but this is known to error and not run. There are a number of NVM values you can change manually;
715-510 – Vertical Registration Side 1
715-511 – Vertical Registration Side 2
711-140 – Lead Edge Side 1
715-515 - Lead Edge Side 2 (7845/55 only)
This only relates to DHDF and not platen glass.