User`s guide

Troubleshooting Troubleshooting Tips - 9
Interrupting a Print Cycle
Interrupting a print cycle and inspecting the photosensitive drum
can help isolate the cause of print quality problems. If the image
on the surface of the drum exhibits the same problem as the
printed page, the fault is before the drum, probably in the
imaging system.
If the image on the drum is OK, the fault is after the drum,
probably in the fuser assembly, transfer block, or high-voltage
power supply. To inspect the drum in this way, run a print and
wait until the paper clears the synchronization pause at the
registration paper sensor. Open the toner access door, remove the
toner cartridge, and pull back the shield to inspect the drum.