HP Color LaserJet 8550 Multifunction Printer series - Manual (Page 202)

EN Print Quality Problems 201
12 If the speck does not come off,
dampen the hand wipe with isopropyl
alcohol. Use the hand wipe to remove
the spot or speck from the transfer
drum.
Note
If you used isopropyl alcohol to clean the
transfer drum, you might need to print 50
to 100 pages to clean any residual
isopropyl alcohol from the transfer drum.
13 To reinstall the transfer drum, align
the arrows on the ends of the drum
with the matching arrows on the
tracks inside the printer.
14 Push the drum into the printer. Be
sure both sides are inserted
completely.
15 Swing the lower (green) lever to the
left, making sure it clicks into place.
16 Close the right and front doors.
17 When the printer control panel
displays READY , reprint the print job to
verify the repetitive defect has been
eliminated.
If cleaning does not eliminate the
repetitive defect, contact a local
authorized HP dealer or service
representative for service.