Image defects
If specific defects occur repeatedly, print a Print Quality Troubleshooting page and follow the instructions on the first page. If you cannot resolve the problem, use the information in this section to identify the root cause of the problem.
Image defects fall into the following categories. Links to possible causes and recommended solutions are included. In general, the items are listed in order, from minor repairs to major repairs. Check each item in the order in which it appears.
Table 6-3
Image defects
Image defect
Light image
Light color
Dark image
Dark color
Completely blank
All black/solid color
Dots in vertical lines
Dirt on back of paper
Dirt on front of paper
Vertical lines
White vertical lines
Horizontal lines
White horizontal lines
Missing color
Blank spots
Description More information
Image light in all colors
Image light in a particular color
Image dark in all colors
Image dark in a particular color
No image prints
Image is all black or solid color
See Table 6-4 Causes for light images on page 211 .
See Table 6-5 Causes for one color printing light on page 211
.
See Table 6-6 Causes for dark images on page 212 .
See Table 6-7 Causes for one color printing darker than others on page 212 .
See Table 6-8 Causes for a completely blank image on page 213 .
See Table 6-9 Causes for an all black or solid colored image on page 213 .
White dots appear in image
Dirt on the back of the page
Dirt on the front of the page
Vertical line appears in image
White vertical line appears in image
Horizontal line appears in image
See Table 6-10 Causes for vertical lines of white dots on page 213 .
See Table 6-11 Causes for dirt on the back of the paper on page 214 .
See Table 6-12 Causes for dirt on the front of the paper on page 214 .
See Table 6-13 Causes for vertical lines on page 214
.
See Table 6-14 Causes for white vertical lines on page 215 .
See Table 6-15 Causes for horizontal line on page 215 .
White horizontal line appears in image
Image in a particular color does not come out in color
See Table 6-16 Causes for white horizontal lines on page 215 .
See Table 6-17 Causes for a missing color on page 216
.
Blank spots appear in image
See Table 6-18 Causes for blank spots on page 216 .
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Table 6-3
Image defects (continued)
Image defect
Poor fusing
Distorted Image
Color misregistration
Smearing
Misplaced image
Reversed color
Snail tracks
Description
Toner image is not fully fixed on the media
Image is distorted
Some color is misregistered
Image smeared in whole or in part
Whole image is incorrectly placed
White in image is output in color, and color is output in white
Streaks on the page (that look like snail tracks); the media might wrinkle
More information
See Table 6-19 Causes for poor fusing on page 216
.
See Table 6-19 Causes for poor fusing on page 216
.
See Table 6-21 Causes for color misregistration on page 217 .
See Table 6-22 Causes for smearing on page 218 .
See Table 6-23 Causes for a misplaced image on page 218 .
See Table 6-24 Causes for reversed color on page 218
.
See Table 6-25 Causes for snail tracks on page 218
.
Light image
Table 6-4
Causes for light images
Cause
The image density is not adjusted correctly
The transfer unit has deteriorated
Poor secondary-transfer-bias contacts exist
Solution
Calibrate the printer.
If the transfer unit is at the end of its life or its surface has deteriorated, replace the transfer unit.
On the secondary transfer roller, check the bias contacts to the high-voltage PCB. Clean them, if necessary.
Replace defective parts and deformed or damaged contacts.
Replace the secondary transfer charging roller.
The secondary transfer charging roller is deformed or has deteriorated
The high-voltage PCB is defective
The DC controller PCB is defective
Replace the high-voltage PCB.
Replace the DC controller PCB.
Light color
Use an external device to print a solid-filled image as an example of the problem. As the sample prints, turn the printer off and remove the cartridge. Open the cartridge shutter. If the toner image on the drum before transfer is light, go to step A. If the toner image on the photosensitive drum is not fully transferring to the transfer unit, go to step B in the following table.
Table 6-5
Causes for one color printing light
Step A
Cause
Poor developing-bias contacts
Solution
Check the developing-bias contacts to the high-voltage PCB.
Clean the contacts as necessary.
Image defects 211
Table 6-5
Causes for one color printing light (continued)
Step B
Cause
Deteriorated cartridge (photosensitive drum)
Defective high-voltage PCB
Defective DC controller PCB
Poor primary-transfer-bias contacts
Solution
Replace any deformed or damaged contacts.
Replace the cartridge that produces the light color.
Replace the high-voltage PCB.
Replace the DC controller PCB.
On the transfer unit, check the primary transfer-bias-contacts to the high-voltage PCB. Clean the contacts as necessary. Replace any deformed or damaged contacts.
Replace the transfer unit.
Deformed or deteriorated primary-transfer charging roller
Defective high-voltage PCB
Defective laser/scanner unit
Defective DC controller PCB
Replace the high-voltage PCB.
Replace the laser/scanner unit.
Replace the DC controller PCB.
Dark image
Table 6-6
Causes for dark images
Cause
Image density is not adjusted correctly
Color misregistration sensor lens is dirty
Color misregistration sensor is defective
Environmental sensor is defective
DC controller PCB is defective
Solution
Calibrate the printer.
Clean the color misregistration sensor lens.
Replace the color misregistration sensor.
Replace the environmental sensor.
Replace the DC controller PCB.
Dark color
Table 6-7
Causes for one color printing darker than others
Cause
Poor contacts with the primary-charging bias, developing bias, or drum grounding
High-voltage PCB is defective
DC controller PCB is defective
Solution
On the cartridge that is producing the darker color, check the primary-charging bias and developing-bias contacts to the high-voltage PCB, or the drum-grounding contacts.
Clean the contacts as necessary. Replace any deformed or damaged contacts.
Replace the high-voltage PCB.
Replace the DC controller PCB.
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Completely blank image
Table 6-8
Causes for a completely blank image
Cause
High-voltage PCB is defective (no developing-bias output)
DC controller PCB is defective
Solution
Replace the high-voltage PCB.
Replace the DC controller PCB. Calibrate the printer after replacing the DC controller.
All black or solid color
Table 6-9
Causes for an all black or solid colored image
Cause
Poor contacts with the primary-charging bias, developing bias, or drum grounding
Cartridge (primary-charging roller) is defective
High-voltage PCB is defective
DC controller PCB is defective
Solution
On the cartridge that is producing the solid color, check the primary-charging bias and developing-bias contacts to the high-voltage PCB, or the drum-grounding contacts. Clean the contacts as necessary. Replace any deformed or damaged contacts.
Replace the cartridge that is producing the solid color.
Replace the high-voltage PCB.
Replace the DC controller PCB. Calibrate the printer after replacing the DC controller.
Dots in vertical lines
Table 6-10
Causes for vertical lines of white dots
Cause Solution
Transfer unit or primary-transfer charging roller is deformed or deteriorated
Secondary-transfer charging roller is deformed or deteriorated
Replace the transfer unit.
Replace the secondary-transfer charging roller.
High-voltage PCB is defective
DC controller PCB is defective
Replace the high-voltage PCB.
Replace the DC controller PCB. Calibrate the printer after replacing the DC controller.
Dirt on back of paper
If the defect is repetitive dirt, go to step A; if not, go to step B.
Image defects 213
Table 6-11
Causes for dirt on the back of the paper
Cause Solution
A
Repetitive dirt (dirty registration roller, pressure roller, feed roller, fuser delivery roller, or face-down delivery sub-roller)
See
Table 6-26 Causes of repetitive defects on page 220 to identify the roller with which the problem
is associated. Clean the dirty roller. Replace the roller if the dirt does not come off.
B
Dirty cassette pickup roller, feed guide, fuser inlet guide, or fuser delivery guide
Clean any dirt from the rollers. Replace the roller if the dirt does not come off.
Dirt on front of paper
If the defect appears in a particular color, go to step A. If it does not appear in a particular color and it is repetitive, go to step B. If it is not repetitive, go to step C.
Table 6-12
Causes for dirt on the front of the paper
A
B
C
Cause Solution
Defective cartridge (deteriorated toner or scratches on the developing cylinder, photosensitive drum, or primary charging roller)
Replace the cartridge of the color that matches the defect.
Repetitive dirt (dirty registration sub-roller, fuser sleeve, feed sub-roller, or face-down delivery roller)
See
Table 6-26 Causes of repetitive defects on page 220 to identify the roller with which the problem
is associated. Clean the dirty roller. Replace the roller if the dirt does not come off.
Dirty multipurpose tray pickup roller Clean dirt from the roller. Replace the roller if the dirt does not come off.
Defective transfer unit
Defective transfer-unit cleaning blade
Check the transfer-unit surface. If it is scratched or dented, replace it.
Replace the transfer unit.
Vertical lines
Table 6-13
Causes for vertical lines
Cause
Photosensitive drum has grooves on the circumference
Fuser sleeve has grooves on the circumference
Solution
Replace the cartridge that produces the vertical lines.
Replace the fuser.
White vertical lines
If the lines appear in a particular color, go to step A. If they appear in a full-color print, go to step B.
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Table 6-14
Causes for white vertical lines
Cause
A
Scratches on the circumference of the developing cylinder (print cartridge)
Scratches on the circumference of the photosensitive drum
B
Vertical scratches on the transfer unit
Vertical scratches on the fuser sleeve
Solution
Replace the print cartridge.
Replace the print cartridge.
Replace the transfer unit.
Replace the fuser.
Horizontal line
If the line appears in a particular color, go to step A. If it appears in the full-color print, go to step B.
Table 6-15
Causes for horizontal line
Cause Solution
A
The developing cylinder is deformed by remaining engaged with the photosensitive drum for too long.
Horizontal scratches on the photosensitive drum
(cartridge)
See Table 6-26 Causes of repetitive defects on page 220
to determine whether a photosensitive drum is involved. If so, replace the cartridge.
The print-cartridge cleaning blade leaves a line of toner on the drum (C-blade blur). The line repeats every
77 mm (3.0 inches).
At the printer control panel, set CONFIGURE DEVICE/
PRINT QUALITY/OPTIMIZE/ PRE-ROTATION=ON.
B
Horizontal scratches on the fuser sleeve
See Table 6-26 Causes of repetitive defects on page 220
to determine whether a developing cylinder is involved. If so, print about 20 pages to solve the problem.
If the problem is not resolved, replace the cartridge.
See Table 6-26 Causes of repetitive defects on page 220
to determine whether a fuser sleeve is involved. If so, replace the fuser.
White horizontal line
If the line appears in a particular color, go to A. If it appears in full color, go to B.
Table 6-16
Causes for white horizontal lines
Cause
A
Horizontal scratches on the photosensitive drum
(cartridge)
B
Horizontal scratches on the transfer unit
C
The fuser sleeve is deformed by remaining engaged with the pressure roller for too long
Solution
See
Table 6-26 Causes of repetitive defects on page 220 to determine whether a photosensitive drum
is involved. If so, replace the print cartridge.
Check the transfer unit surface for horizontal scratches. If any, replace the transfer unit.
See
Table 6-26 Causes of repetitive defects on page 220 to determine whether the fuser sleeve is
involved. If so, replace the fuser.
Image defects 215
Color missing
Table 6-17
Causes for a missing color
Cause
Defective laser shutter
Poor developing-bias contacts
Defective cartridge (primary-charging roller)
Laser/scanner unit is defective
High-voltage PCB is defective
DC controller PCB is defective
Blank spots
Table 6-18
Causes for blank spots
Cause
Poor secondary-transfer-bias contacts
High-voltage PCB is defective
DC controller PCB is defective
Poor fusing
Table 6-19
Causes for poor fusing
Cause
Media is not within specifications
Fuser is not within nip-width specifications
Fuser sleeve is scarred or damaged
Pressure roller is scarred or damaged
Printer is not properly set for media type
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Solution
Check the problem color laser shutter. Clean the shutter as necessary. Replace the shutter if it is deformed or damaged.
For the cartridge with the problem (color missing), check the developing-bias contacts to the high-voltage PCB.
Clean contacts, if dirty. Replace defective parts if the contacts are deformed or damaged.
Replace the problem (color missing) color cartridge.
Replace the laser/scanner for any missing color. Calibrate the printer after replacing the laser/scanner.
Replace the high-voltage PCB.
Replace the DC controller PCB. Calibrate the printer after replacing the DC controller.
Solution
On the secondary-transfer roller, check the bias contacts to the high-voltage PCB. Clean the contacts as necessary.
Replace any deformed or damaged contacts.
Replace the high-voltage PCB.
Replace the DC controller PCB. Calibrate the printer after replacing the DC controller.
Solution
Use media that meets specifications.
See
Table 6-26 Causes of repetitive defects on page 220 to determine whether a fuser sleeve is
involved. If so, replace the fuser sleeve unit.
Replace the fuser.
See
Table 6-26 Causes of repetitive defects on page 220 to determine if a pressure roller is involved.
If so, replace the fuser.
Set the printer for the media type being used.
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Table 6-19
Causes for poor fusing (continued)
Cause
Thermistor is deteriorated
DC controller PCB is defective
Solution
Replace the fuser.
Replace the DC controller PCB. Calibrate the printer after replacing the DC controller.
Image distortion
Table 6-20
Causes for distortion or blurring
Cause
Transfer unit is defective
Secondary-transfer roller is defective
DC controller PCB is defective
Solution
Replace the transfer unit. Calibrate the printer after replacing the transfer unit.
If it does not rotate smoothly or is deformed, replace the secondary-transfer roller.
Replace the DC controller PCB. Calibrate the printer after replacing the DC controller.
Color misregistration
If the misregistration occurs in a particular color, go to A. If it occurs in all colors, go to step B. If another misregistration issue is evident, perform the steps in order.
Table 6-21
Causes for color misregistration
Cause
The printer is not calibrated correctly
A
Cartridge is defective
Cartridge drive gears are worn or chipped
B
Color misregistration sensor is dirty
Color misregistration sensor is defective
Transfer unit is defective
Drive gears are worn or chipped
Image drive unit is defective
Laser/scanner unit is defective
DC controller PCB is defective
Solution
Calibrate the printer.
Open the front door and remove the ETB shipping locks on each side of the ETB assembly, toward the bottom.
Check if the photosensitive drum in the problem cartridge rotates smoothly. If not, replace the cartridge.
Check the drive gears connected to the problem cartridge.
If a gear is worn or chipped, replace the gear.
Clean the color misregistration sensor lens.
Replace the color misregistration sensor.
If the transfer unit does not rotate smoothly, replace it.
Check the drive gears between the image drive unit and the drum motor. If one is worn or chipped, replace it.
Replace the image drive unit.
Replace the laser/scanner unit.
Replace the DC controller PCB.
Image defects 217
Smearing
Table 6-22
Causes for smearing
Cause Solution
Poor contacts exist to each cartridge and printer grounding Clean the grounding contacts on each cartridge and the printer. If the problem remains after cleaning, check the contacts for damage. Replace any deformed or damaged parts. Make sure that all contacts are connected correctly.
The movement of the fuser front paper sensor lever is not smooth
Reseat the lever to make the movement smooth.
Foreign substances or dirt on the fuser inlet guide Clean the fuser inlet guide.
Misplaced image
Table 6-23
Causes for a misplaced image
Cause
The oblique rollers are worn (if problem only occurs on the back side of duplex printing only)
DC controller PCB is defective
Solution
Replace the oblique rollers.
Replace the DC controller PCB. Calibrate the printer after replacing the DC controller.
Reversed color
Table 6-24
Causes for reversed color
Cause
The FFC that connects the DC controller to the formatter is not correctly connected
DC controller PCB is defective
Solution
Reseat the FFC to the DC controller PCB J1001.
Replace the DC controller PCB.
Snail tracks
Table 6-25
Causes for snail tracks
Cause Solution
This occurs in high-temperature, high-humidity environments on the second side of duplexing jobs when the fuser pressure roller is bent.
Replace the fuser.
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NOTE
See the print modes in CONFIGURE DEVICE/ PRINT QUALITY/ PRINT MODES to associate each paper type with a specific print mode. For example, several “BEST” print modes can be set for a specific media type to enhance print quality. Results will vary, depending on the media being used.
See the OPTIMIZE setting for additional print-quality adjustments.
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