HP M750 series

Problem Sample Cause Solution
The back of the page is dirty.
The secondary transfer roller is
dirty.
Replace the secondary transfer roller.
The fuser inlet guide or
separation guide is dirty.
Clean the dirty parts. If the dirt does
not come off, replace the guide.
The pressure roller is dirty. Run the cleaning page several times. If
the dirt does not come off, install a
fuser cleaning kit. If the issue persists,
replace the fuser.
Vertical streaks or bands appear
on the page.
Scratches are present on the
circumference of the
photosensitive drum.
Replace the print cartridge of the color
that matches the defect.
Scratches are present on the
circumference of the fuser
roller.
Replace the fuser.
Scratches are present on the
circumference of the ITB.
Replace the ITB.
The ITB drive roller is deformed
or has deteriorated.
The ITB cleaning mechanism is
malfunctioning.
Vertical white lines appear in a
particular color.
The laser beam window is dirty. Execute the Clean Laser Glass item in
the Calibration/Cleaning submenu (in
the Device Maintenance menu)
If the error persists, manually clean
the window and remove any foreign
substances.
Scratches are present on the
circumference of the
developing cylinder or
photosensitive drum.
Replace the affected print cartridge.
If the problem persists, replace the
affected print cartridge.
The laser/scanner-unit mirror is
dirty.
Replace the laser/scanner assembly.
Vertical white lines appear in all
colors.
Horizontal scratches on the
fuser roller.
Replace the fuser.
Scratches are present on the
circumference of the ITB.
Replace the affected print cartridge.
Replace the ITB.
Horizontal lines appear on the
page.
Repetitive horizontal lines
appear.
Use the repetitive defects ruler to
identify the dirty roller. Clean the
roller. If the roller cannot be cleaned,
replace the fuser.
Horizontal scratches are
present on the photosensitive
drum.
Replace the print cartridge of the color
that matches the defect.
Horizontal scratches are
present on the fuser roller.
Replace the fuser.
ENWW Solve image-quality problems 519