HP Printing Korea

Image Quality
Troubleshooting
Guide (IQTG)
For A3 Laser Multifunction Printers

HPPK H/W TME

Last update: 2022. July

1 / 87
Table of contents

Unit 1. Introduction ……………………………………….…………………………………………….…3

1. Checklist before reporting issues

2. Basic troubleshooting tools (Embedded tools)

Unit 2. Image Category …………………………………………………………………………….13

1. lines or bands ……………………….…..…………………………..14

1) lines 2) bands

2. spots …………………………………….….………………………………24

periodic spot / micro white spot / white spot / gray spot / solid spot

3. nonspecific shape ………………..……….……………………….29

1) dirty image 2) stains 3) torn/ scratch

4. image related ….…………………..……….….………….…………….37

1) image position accuracy 2) color registration 3) image fading 4) image noise

5. Others ………………………………..……………..….……………….…….50

1) blank page 2) black print 3) background

Unit 3. Field solutions ……………………………………………………………………………..52

1. Highly requested image quality problems …………53

2. SI cases ………………………………………………………………………..68

2 / 87
Unit 1. Introduction
In this unit, you can find some CHECKLISTS and BASIC TROUBLESHOOTING TOOLS which are useful in the
first stage of troubleshooting the image quality problems in the market. These basic methods may not
guide you to find the strong ultimate solution to address the cause of image quality problem in no time,
but can be a base camp in the long journey to find the solution of image quality problems.

1. Checklist before reporting issues to higher level tech support

: Try to find the causes from the checklist as below

1) Supplies and Long Life Consumables(LLCs)

: Look at the life remaining of each LLC and check the state of each consumable component. Sometimes
the problem occurs due to lack of TONER or exhausted life of LLCs.

2) Printer driver
: Customers have several options for printer driver such as Discrete driver, Universal Print Driver, smart
Universal Print Driver, and there are different settings for each driver. So, review the print settings on
each case.

3) Print or Copy options

: While we are not aware of settings of Print / Copy options, the group of settings affect the devices as
they were supposed to do even if the settings are not proper at the scene. It’s worth seeing at least
once.

4) Environments
: It is always recommended that we would better to find the unique environments of problematic devices
comparing with other ordinary customer’s. This is one of the required check points.

5) Internal reports
: Don’t forget to read the latest information of the device as ground rules.

3 / 87
2. Basic troubleshooting tools (Embedded tools)

To analysis with these patterns, it requires some equipment such as a high-resolution scanner and S/W
tools to verify skewing, jitter, and color plane registration.
Therefore, it is not easy for field engineers to make a judgement with these patterns. These are mainly
used when R&D engineers need to analysis PQ issues in the lab.
Sometimes Technical Market Engineers(TME) requests field engineers to print out these patterns and to
send them for further investigation.

1) Investigate <Embedded Test patterns> on the device

[Gemstone 1.x ]  Service mode > Diagnostics > Print Test patterns
[Gemstone 2.0 ]  Support Tools > Print Quality Pages > Advanced Print Quality Pages

[EP Calibration Pattern]

- To see the quality and density of basic
Electrophotographic(EP) patterns

<Pattern 1- Contone> <Pattern 2 - Halftone>

4 / 87
[Tone Curve Int Calibration pattern]

- Internal Calibration Pattern for Cyan and

Black : To see their color quality and
density

- Internal Calibration Patten for Yellow and

Magenta : To see their color quality and
density

< CK Pattern > < YM Pattern >

[Tone Curve Ext Measurement Page]

- Calibration Pattern for C/M/Y/K

: To see their color quality and
Tone Reproduction Curve (TRC)

5 / 87
 [Mechanical Banding Page]

<Black Mechanical <Cyan Mechanical <Magenta Mechanical

Banding Page> Banding Page> Banding Page>

- To see if there is any problem with the printer about banding or image jitter

- To identify image defects that come mainly from gears and rollers

- There's no yellow banding page due to light print, limited number of built-in images

6 / 87
[Color Registration Check for Motion]

- To see the quality of color registration (=color plane

registration - CPR)

7 / 87
2) Apply <Adjustment tools> to the cases in the field

a. X3A92-67925 / Kit-Service Sheets for Calibration

- Goal
① These charts are used for measuring skewed images when copying or scanning
② There are 2 kinds of original size  A4 size (JC68-02474A), Letter size (JC68-02475A)

- Usages
① Most skewed images problems occurs on the ADF(Automatic Document Feeding) unit
② Prepare 10 to 20 sheets of this chart, and put them all on ADF tray.
③ Scan or copy all of them, and then look at the outputs to see if how much the images are skewed.
④ Single copy of these charts can help sometimes, but multiple copies would be better to measure the
degree of the image skewing.
⑤ Do scan or copy several times for better data accuracy.

<Sample document>

8 / 87
 -------------------------------------------------------------------------------------------------------------------
1. The status in the site
- An engineer specialized in the scanner technology had visited the customer and he installed the
PoC(Proof of Concept) firmware in the site after some examination.

-------------------------------------------------------------------------------------------------------------------

9 / 87
 3

A3
size

Ledger
size

Item Description Use

[1] Grid pattern adjusting margin and magnification
[2] Black patches adjusting skew error
[3] Barcode the reproduction of the barcode
[4] Note area recording the date, conditions, and so on
[A] Halftone band banding and jitter(K 50%)
[B] [L] Resolution patterns resolution
[C][D][E] Images color reproduction
[F] Map image fine line reproduction
[G] Color patches color reproduction and uniformity
[H] Gradation pattern toner reproduction of seven color(C,M,Y,K,R,G,B/10~100%)
[I] Color/Mono text the reproduction of color, mono text
[J] Multilingual feature the reproduction of small text
[K] White gap pattern color to color, color to mono white gap
[M] Rulers the magnification error(unit: cm)
[N] Rulers the magnification error(unit: inch)
10 / 87
 [shading sheet]
: This sheet is for recognizing the basic value of white color
for scanner. Before performing scan jobs, scanner reads the
shading sheet to make the scan image the same color and
brightness.

1) Scanners have the shading sheet within the way of scanner module like the picture below, and a
separate shading sheet as a service part (JC63-05055A) is the same one. But when performing shading
tests for DSDF (Dual Scan Document Feeder), this separate shading sheet(service part) is necessary.

[shading sheet in the scanner]

2) After replacing ADF unit (DSDF unit) or main PCA, the shading test for ADF unit must be carried out.
3) Shading test in the Service mode (Gemstone 1.x)
: Service mode > Diagnostics > Scanner Diagnostics > Shading Test > Shade and Print Report(ADF)
4) Pre-installed shading sheet in Gemstone 2.0
: The shading sheet is unnecessary for Gemstone 2.0
: The scanner is automatically adjusted using the installed white bar whenever the scanner is activated.

11 / 87
 b. Auto Tone adjustment
① Usage : used on MONO products when
- Image density is too high/low
- "CTD density sensor is dirty" error message
- Always after cleaning CTD sensors

② Route : Service mode> Diagnostics> Image Management> Auto tone adjustment> [Normal] or [Full]
- Normal : Normal TRC(Toner Reproduction Curve) control performs
- Full : Full TRC control performs

c. Color toner density(CTD) sensor cleaning and setting standard tone adjustment
① Usage : used on COLOR products when
- Intermediate Transfer Belt(ITB) is replaced
- Image density is too high/low
- Error message "CTD sensor is dirty" shows up
- Always perform it after cleaning CTD/ACR sensors

② Route
: Service mode> Diagnostics> Image Management> Auto tone adjustment> CTD Sensor cleaning
: Service mode> Diagnostics> Image Management> Setting Standard Tone

d. Calibration/Cleaning for Gemstone 2.0

① Usage : Print/Copy images improvement
- ACR Reference Adjustment
- Auto Color Registration / Full Auto Color Registration
- Custom Color
- Auto Tone Adjustment/ Manual Tone Adjustment
- CTD Sensor Cleaning
- Setting Standard Tone

② Route
: Support Tools> Maintenance menu> > Calibration/Cleaning > Advanced Calibration Support > XXXX

12 / 87
Unit 2. Image category

In this unit, you see various simplified pictures of image quality problem that can be found in the market.
Between local tech supports and high level tech supports, this will be one of good media to speak about
unique image quality problems, and if we can make clear definitions of the image quality problems based
on this document, it will help each other communicate.
Here are 5 big boundaries and details under each boundary.

Lines/bands Spots nonspecific shape image others

- Lines(streaks) - periodic spot - dirty image - image position - blank page

- Bands - micro white spot - stains accuracy - black print

- white spot - torn/scratch - color registration - background

- gray spot - image fading

- solid spot - image noise

13 / 87
1. Lines or bands

1-1 . Periodic bands/lines

• Symptom : Repetitive lines which are perpendicular to paper process direction failure
with respect to roller periods (horizontal direction)

• Related units : Drive / Developer/ Frame / LSU / Feeding / ITB or PTB / Fuser

• Countermeasures

1) measure the length of repeated lines or bands

2) search for the unit where the defective lines or bands came from

• Additional info.

1) see the table for more information

: sample images / Table1. Repetitive Image defect ruler

14 / 87
[sample images]

- Background on black Drum unit with period

- Background on magenta Drum unit with period

15 / 87
- Periodic lines

16 / 87
Table1. Repetitive Image defect ruler

E87740 - E87770 Products

Roller Unit Period (mm)
OPC Drum 94.5
Charge roller Drum 37.7
Magnetic roller Development 38.9
ITB drive roller ITB 77.7
T2 Roller Transfer unit on Side cover 75.4
T1 Roller ITB 44
ITB Guide Roller ITB 37.7
Fuser Pressure roller Fuser 115.9
Fuser Belt Fuser 110
Fuser Exit Fuser 28.3

17 / 87
 E78625 - E78635 Products
Roller Unit Period (mm)
OPC Drum 94.2
Charge roller Drum 37.7
Magnetic roller Development 31.5
ITB drive roller ITB 77.7
T2 Roller Transfer unit on Side cover 60.9
T1 Roller ITB 44
ITB Guide Roller A ITB 38.7
ITB Guide Roller B ITB 37.7
Fuser Pressure roller Fuser 94.25
Fuser Belt Fuser 110

E78523 - E78528 Products

Roller Unit Period (mm)
OPC Drum 94.5
Charge roller Drum 37.7
Magnetic roller Development 31.5
ITB drive roller ITB 77.7
T2 Roller Transfer unit on Side cover 60.9
T1 Roller ITB 44
ITB Guide Roller A ITB 38.7
ITB Guide Roller B ITB 37.7
Fuser Pressure roller Fuser 94.25
Fuser Belt Fuser 110

18 / 87
 E82640 - E82670 Products
Roller Unit Period (mm)
OPC Drum 188.6
Charge roller Drum 37.7
Magnetic roller Development 36.9
PTB belt PTB on Side cover 157.1
Fuser Pressure roller Fuser 115.9
Fuser Belt Fuser 110
Fuser Exit Fuser 28.3

E73125 - E73135 Products

Roller Unit Period (mm)
OPC Drum 94.5
Charge roller Drum 37.7
Magnetic roller Development 31.8
Transfer roller TR on Side cover 61.6
Fuser Pressure roller Fuser 89.61
Fuser Belt → Heat roller Fuser 94.25

E73023 - E73028 Products

Roller Unit Period (mm)
OPC Drum 94.5
Charge roller Drum 37.7
Magnetic roller Development 31.8
PTB belt → Transfer roller PTB on Side cover → TR on Side cover 61.6
Fuser Pressure roller Fuser 89.61
Fuser Belt Fuser 94.25

19 / 87
1. Lines or bands

1-2 . Non-periodic bands/lines

• Symptom : Single line or lines or band which are perpendicular to paper process
direction failure (horizontal direction & generally not repetitive)

• Related units : LSU / Electrophotographic-related(EP) / HVPS

• Countermeasures

1) LSU : look at (the Hsync signal detection/ BD sensor/ Photo diode)

2) EP : check if there is anything wrong with image transferring

3) HVPS : any high voltage ripples in the system

• Additional info. : -

20 / 87
[sample image]

- From dent(60nm deep) on LSU mirror and comes with error(63.00.xx) - Ruby, Jade

paper moves this

way

21 / 87
1. Lines(streaks) or bands

1-3 . Non-periodic bands/lines (vertical)

• Symptom : Line(s) or band(s) which are in the same paper process direction failure
(vertical direction)

• Related units : LSU / Electrophotographic-related(EP) / hardware components

• Countermeasures (known cases)

1) Black line from OPC K : Toner deposited at CR drive contact

2) Dark black bands: multiple dark bands due to transfer faults in H/H environment

3) Deve streak : streak due to dirt accumulated in developer

4) Vertical streak : due to wrinkle on ITB(image transfer belt)

• Additional info.: sample images

- vertical lines

22 / 87
- white vertical line : circumferential contamination on

paper moves this way

- vertical white band when there is any foreign material within ITB cleaner

23 / 87
2. spots

 Periodic spots

• Symptom : spot appeared by period per unit

• Related units : OPC

• Countermeasures : spots on OPC

• Additional info. :

 Micro white spot (transfer)

• Symptom : small white spots on the image

• Related units : transfer-related

• Countermeasures : This occurs when transfer voltage(Vi) is stronger than discharge

voltage(Vd)  Vi > Vd

1) adjust T2 bias

2) change high resistance paper (at duplex printing)

3) avoid Low humidity environment

4) check if it is okay with toner electric charge

• Additional info. : sample images

24 / 87
 - OPC spot / Micro white spot / White spots

- Micro white spot

25 / 87
 White spot

• Symptom : large white spots on the image

• Related units : Electrophotographic-related(EP)

• Countermeasures : The bundles of black toner particles causes large spots(100 ~

500um), so we recommend the replacement of brand new toner.

• Additional info. : sample image

- White spots from drum

26 / 87
 Gray spot

• Symptom : gray color spots on the image

• Related units : transfer-related

• Countermeasures : This problem occurs when the carrier develops on the image or
the carrier contaminated on OPC. We should adjust the voltages about image
transferring.

• Additional info. : sample images

- Gray spot / Solid spot

27 / 87
 Solid spot

• Symptom : darker spots than the image

• Related units : transfer-related

• Countermeasures : This is one of re-transfer effects. The air gaps created by the
carrier on non-image area or contaminated area on ITB(Image transfer belt) moves
to the next pod(T1 or T2) and the area appears as solid spot on the next image.

1) adjust T1 bias, T2 bias

2) examine at the status of carrier developing

• Additional info. : -

28 / 87
3. Nonspecific shape

3-1. Image Contamination (dirty)

 Edge dirty

• Symptom : dirty areas on the edge of paper

• Related units : OPC, cleaning blade

• Countermeasures : This is mainly caused by the OPC surface which was not cleaned
properly.

 Investigate OPC unit and replace with a new one if possible

• Additional info.

: This can occur when the OPC surface damaged by the carrier affects the cleaning

blade.

29 / 87
 Develop carrier leakage

• Symptom : dirty areas on the paper

• Related units : Electrophotographic-related(EP)

• Countermeasures : Due to toner scatter around

magnetic roller, the carrier smeared on paper

1) We should examine the followings.

 Electric charge potential/ the cause of toner scatter/ size of Dr.gap, TC control/

HVPS

• Additional info. : -

30 / 87
 Transfer blur/ Satellite

• Symptom : dirty area around the image or

characters

• Related units : Transfer-related

• Countermeasures : Toner was attracted to the

paper more than expected.

1) We should examine the followings.

T1 bias or T2 bias/ High resistance paper/ Low humid environment/ toner electric charge

• Additional info. : sample image

31 / 87
 Fuser offset

• Symptom : dirty particles on the paper

• Related units : Fuser

• Countermeasures : This came from particles of a torn fuser belt

• Additional info. : -

32 / 87
3. nonspecific shape

3-2. Image stains

 Periodic stains - Unit period stain

• Symptom : Unit period stain

• Related units : Electrophotographic-related(EP)

Transfer (T1, T2), Fuser

• Countermeasures : Find the cause of unit period stain.

We have a few cases about T2 period stain. (For E876xx, T2 roller’s period is 75.4mm)

• Additional info. : -

33 / 87
 Periodic stains - Negative ghost

• Symptom : light images appears on paper

• Related units : Electrophotographic-related(EP),

• Countermeasures : There is a difference of image

density due to transfer bias accumulation on OPC non-
image surface and it affects on OPC surface potential.
Check the following points such as T1 transfer bias/
OPC level thickness/ OPC sensitivity/ OPC surface potential.

• Additional info. : -

 Fuser wrinkles/squashed stain

• Symptom : stain appears on overall or partial region

of image, due to fuser wrinkle or fuser squash

• Related units : Fuser

• Countermeasures : Replace fuser

• Additional info. : -

34 / 87
 Smear

• Symptom : swept image appeared normally on

the center to end of the paper

• Related units : Fuser

• Countermeasures : Stain mark appears when image

get closed to or passed by fuser roller or belt before
fusing process

• Additional info. : -

[A3 duplex printing - smear]

35 / 87
3. nonspecific shape

3-3. Image scratch/torn (mark)

 Transfer scratches/torn

• Symptom : Insufficient transferring toner by electric

field leakage

• Related units : Transfer(T2)

• Countermeasures : Check the followings.

T2 bias/ High resistance paper/ duplex print/ low

humid environment

• Additional info. : -

 Fuser scratch/torn

• Symptom

1.Image tearing occurs according to the fuser roller

period

2.The residual toner of the fuser affects the image

(hot offset)

• Related units : Fuser

• Countermeasures : Adjust fuser temperature /

avoid glossy paper

• Additional info. : -

36 / 87
4. Image related

4-1. Image position accuracy

• Margin

• Symptom : left/right/upper/lower shifted print or

copy

• Related units : Feeding/Frame/scan/ S/W

• Countermeasures

1) paper side margin : adjust the paper guides in tray

2) top margin : clutch failures OR slippery parts such as paper rollers
3) Others : pickup gear stopper broke or faulty assembly (feed roller, roller pressure
spring, regi roller)
• Additional info. : -

• Skew

• Symptom : skewed print or copy

• Related units : Feeding/Frame/scan

• Countermeasures

1) adjust the paper guides in tray

2) see if there is any faulty assembly such as Feed roller,
Roller pressure spring, regi-roller and etc

• Additional info. : -

37 / 87
 Magnification(stretch)

• Symptom : magnified/reduced image on print or

copy

• Related units : Feeding/Frame/scan/ S/W

• Countermeasures

1) Make sure the paper size is selected incorrectly

2) See if feeding/Frame assembly work correctly

3) See if there is any (mechanical + scan scaling) failure

• Additional info. : -

 ADF copy diagonal lines / waves

• Symptom : diagonal lines or waves when copy

• Related units : ADF hinge

• Countermeasures

: Make sure the ADF hinges are aligned correctly in the

platen

• Additional info. : -

38 / 87
4. Image related

4-2. Color registration

 Color text/Line registration failure

• Symptom : color text overlaps turns out to be

blurry

• Related units : Drive / LSU

• Countermeasures

: 1) clean the Color Plane Registration (CPR) assembly or replace it.

2) check the CPR report (or Auto Color Registration report) and perform CPR
adjustment.

3) replace the main drive assembly or LSU (Laser Scanning Unit)

• Additional info.

- sample images

39 / 87
 White gap/composite area registration failure

• Symptom : white gap appearance

• Related units : Drive / LSU

• Countermeasures

1) clean the Color Plane Registration (CPR) assembly or replace it.

2) check the CPR report (or Auto Color Registration report) and perform CPR
adjustment.

3) replace the main drive assembly or LSU (Laser Scanning Unit)

• Additional info.

1) clean the Color Plane Registration (CPR) assembly or replace it.

2) check the CPR report (or Auto Color Registration report) and perform CPR
adjustment.

3) replace the main drive assembly or LSU (Laser Scanning Unit)

40 / 87
4. Image related

4-3. image fading

 Image fade - EP K image fade

• Symptom : temporary black density fade due to the

lack of margin for Black toner/developer ratio

• Related units : Electrophotographic-related(EP)

• Countermeasures

1) This problem generally occurs in room

temperature/low humidity environments.

2) Black toner/developer ratio margins should be adjusted higher than now

• Additional info. : -

 Image fade - Deve K image fade

• Symptom : Image fade occurs throughout the whole

page

• Related units : Developer

• Countermeasures : Replace with new developer units

• Additional info. : This occurs because the doctor

blade gap does not meet the required specifications and this adjustment is performed
in the manufacture

41 / 87
 Image loss (overall or partial)

• Symptom : overall or partial image color loss

• Related units : Developer, High voltage contacts

• Countermeasures

1) If the image does not have a specific color, look at

the color developer, and examine the high voltage
contacts in the device chassis.

2) Make sure the color is creating images on ITB(Intermediate Transfer Belt).

• Additional info. : -

42 / 87
 Diagonal fade (auger mark)

• Symptom : white diagonal lines

• Related units : Electrophotographic-related(EP),

developer

• Countermeasures

1) Replace with new developers : Bias fault, ADR fault

2) Replace with new HVPS(high voltage power supply) : Bias fault

3) Replace with a fan or reallocate the device placement : overheat of the device

• Additional info. : ADR is a system that the new developer is entering the developer
unit properly (Auto Developer Replacement)

43 / 87
 Density dark

• Symptom : Density appeared too dark on image

• Related units : Electrophotographic-related(EP),

Developer, LSU

• Countermeasures

1) Make sure CTD sensors are working (not dirty)

2) Make sure the status of TC sensor and TC control are good.

3) change the color management settings to default

• Additional info. : -

44 / 87
 Blurred fluorescent pen image (highlighter)

• Symptom : Blurred fluorescent pen image

• Related units : ISA(Integrated Scanner Assembly)

• Countermeasures

1) Adjust options

- Scan/Copy : Select <Text Mode>

- Image Adjustment > Background Cleanup Level: Select 0 (zero)

[default: 2, Range: 0 – 8]

• Additional info. : Images comparison

45 / 87
4. Image related

4-4. image noise

 Grizzled image1 - retransfer

• Symptom : Toner gets retransferred due to this effect

• Related units : Transfer(T2)

• Countermeasures: Look at the following items

T2 Bias / High resistance paper @duplex printing / low

humid environment / paper insert angle

• Additional info. :This is because the electric field boundary has exceeded

the failure voltage of the Paschen’s Breakdown Voltage

46 / 87
 Grizzled image2 - transfer humidity fault

• Symptom : poor transfer occurs due to transfer

current leakage

• Related units : Transfer(T2)

• Countermeasures : Consider the following

environmental factors

High humidity(wet paper)/ low resistance paper/ current leakage on paper path

/ ITB resistance/ T2 resistance

• Additional info. : -

 Grizzled image3 - hollow character

• Symptom : transfer fault at image center area

• Related units : Transfer(T2)

• Countermeasures : Look at the following items -

T1 welding force / TR bias / toner mobility and electric

charge quantity / reverse polarity toner

• Additional info. : -

47 / 87
 Mottled image

• Symptom : Uneven appearance of print image,

particularly in solid areas

• Related units : Electrophotographic-related(EP),

Transfer-related, fuser

• Countermeasures : Look at the following items -

T1,T2 bias / paper thickness and roughness / fuser temperature and welding force /
surface regularity of pressure roller

• Additional info. : -

48 / 87
 Poor scan image quality

• Symptom : Poor scan image quality (default 200 dpi)

• Related units : ISA(Integrated Scanner Assembly)

• Countermeasures

1) To get a better scanned image quality than a default state

- <High Compression off> OR <Change Color/Black setting>

2) To save default setting at Scan app

• Additional info. :

49 / 87
5. Others

 Blank page

• Symptom : no image on the page

• Related units : HVPS or firmware related

• Countermeasures : Look at the following items -

HVPS PCA failure / firmware faults

• Additional info. : -

 Black print

• Symptom : all black printed page

• Related units : OPC, Deve, HVPS

• Countermeasures : Look at the following items -

OPC(drum) / developer faults / HPVS PCA failure

• Additional info. : -

50 / 87
 Background

• Symptom : toner attached on overall non-image

area on the paper

• Related units : OPC, Deve, Electrophotographic-

related(EP), S/W, H/W

• Countermeasures

1) The change of toner electric charge quantity causes toner scatter

2) HVPS PCA fault

• Additional info. : -

51 / 87
Unit 3. Field solutions
In this unit, you can read the opinions about several types of image quality problems that are frequently
found in the market. And you can also propose what you think about the problem or what you have
experienced before. GBU wants to collect those good ideas and tips, so to share them with everyone who
are interested in the image quality problems. When you have any good thought for this document, contact
the person who is in charge of this document.
 TME in HP printing Korea : changhyeon Shim(chang-hyeon.shim@hp.com)

1. Highly requested image quality problems

The followings are frequently requested service symptoms in the market for print and scan. This is where
you can share your thoughts or experiences with others doing the same thing, and if you have any good
idea for image quality issue, you share and benefit others through this document.

[ Print Quality ] [ Scan Quality ]

No Symptoms No Symptoms
1 lines / streaks / bands 1 lines-stripes
2 light-faded 2 blank pages
3 dirty printouts 3 skewed images
4 smears-smudges 4 light-faded
5 black pages 5 black pages
6 color issues
7 skewing print
8 dots-spots
9 blank pages
10 ghosting

2. Sudden Impact cases

You can find several SUDDEN IMPACT cases on Image quality issue and they are actual good samples of
it. And GBU is expected to add more information in a regular basis.

52 / 87
1. Highly requested image quality problems

[ Print Quality ]

1) lines/ Streaks/ bands

Lines or streaks on images are very frequently occurring problems on site.

In fact, it seemed that lines or streaks on image are regarded as a same type of problem in the field, and
in fact, they look alike.
The only difference is that its name is depending on the people who are reporting the one similar type of
problem. Anyway, their appearance is very alike, so the solutions are also similar.
These problems naturally happen because of paper proceeding, and generally the countermeasures go both
ways.
In some occasion, the countermeasure is found very easily and onsite engineer can remove the problem in
no time, but in other occasion, the countermeasure is hidden for a long time.
When we think of the laser printer image creation process, the paper proceeding is the most powerful
contributor to make lines or streaks on the paper.
In the devices, the paper is passing through in this order. Laser scanning unit (LSU), toner, developer, transfer
unit, retransfer roller, fuser, exit unit and etc.
If we are lucky, we can find the cause among the parts listed up with the order of traveling paper, however,
if we can’t find the cause of the problem within the parts in a row, the concerns start to rise up.
So, when we decided to look into the problem, it would be always better to collect information first as
much as we can replicate all the customer’s conditions in other place, and then to begin with replacing the
suspicious parts.
There is one thing we should remember that we should think of the correlation to the symptoms before
replacing printer parts. GBU has been being seen several cases that replaced printer parts cost more than
the price of brand new machine. it’s sad news.

53 / 87
2) light-faded

Light-faded image means that the image tone is lighter than normal state which the customers expect.
This is very common because maintaining good-looking tone of image is essential to the image creating
device, however, it is not easy to maintain average good quality of images.
In fact, printers are very complicated devices, and it can’t play its full scope of role if any single component
doesn’t serve his own duty.
By the way, the good news is that the light-faded image problem is not involved with several components
and, rather, the problem can be removed by replacing certain one single critical part or by changing one
kind of settings among our available options.

54 / 87
3) dirty printouts

If we speak of "dirty image" of print image quality issues, that will bring lots of image figures, not a single
one.
Dirty images are not so clear to understand as just one kind of obvious result.
Generally, if we call something dirty in the outputs, we imagine in this way that there are undesirable,
intense impacts on the image, and which were not supposed to be there.
Often people describe the dirty images with image contamination just as another expression.
The root cause of this dirty image can be from toner, developer carrier or the trace of certain printer parts.
And to find the root cause, we need to look at the image closely and this will really help find the lead.
In fact, the range of dirty images vary among image quality problems, and the solutions are very different
depending on cases as well.
So it is recommended that we should collect and study various dirty images when we have chances.

55 / 87
4) smears- smudges

In the development stage, I don't think the developers can find this problem of smearing or smudges on
the images much in the lab. And because the main causes of this problem are toner failure, paper attributes,
toner spill, defective fuser, etc, it is likely that another light problem will occur ahead of this problem of
smearing or smudges. For this reason, the developers barely find these smearing or smudges in their place.
What is interesting, by the way, is that this problem is not occurring much in the product development
stage, however it is occurring more in the market than we think.
In fact, replacing supplies can help quickly resolve most of this problem, so most people generally don’t
think it is one of critical problems in the market.

56 / 87
5) black pages

Black pages include darker images than ordinary cases, not only just black colored image on the whole
page.
When it comes to darker images, it feels very different with MONO print products and COLOR products.
In case of MONO products, black pages mean the image is more strong than ordinary cases because MONO
products can depict the outputs with only black and white, and there is nothing else.
In most case, this problem should be solved by adjusting dark tone in the advanced settings or by replacing
supplies with the new ones. Or sometimes toner scatter has been affecting the tone of black color, so we
can resolve this by cleaning all the path through the developing process or transferring process.
However, in COLOR products, black pages mean the outputs seem to have some kinds of black filters on
color images, so images are very weird and uncomfortable. Everything in the images is noticeably dark.
This is uncommon but it happens often than we expect.
We can think this has a lot to do with BLACK toner, but it would be better to think that this is the result of
collaborating all the colors, not just made by BLACK toner.
For this problem, we don’t have the ultimate solution that works 100% in all cases. So, generally it is
recommended the initialization of all color settings in the device, back to the manufacturing default settings.
Because it is very difficult to figure out what factors affect this strange output and what moment it starts
to begin. Most of customers never remembered when it started to begin and how it started to look like.
This is very complicated problem and if we review the history of tech support roughly, the half of cases
were solved by the initialization of the color settings but other half were not. In a lucky case, it suddenly
disappeared as if it had suddenly come in a flash. After all, it’s the same thing that embarrass us in both
cases.

57 / 87
6) color issues

In fact, I didn’t understand exactly what the color issue stands for. But there it was within the service data.
This is just saying that there was something wrong with the colors in the image but it may have been
unusual and beyond the description.
It is obviously about color problems and is likely to occur during the entire lifespan of color printer products.
But nobody knows later what it is if we just leave the explanation as a COLOR ISSUE.
This is one of good reasons to use generally agreeable terms for the printer output problems.
If we don’t know exactly about the matter, we can’t do anything about it.

58 / 87
7) skewing print

Skewing print images are relatively common and easy to fix it.
Theoretically, when we are careful to load paper in the trays every time, the skewing image problems should
be shown on the outputs. Paper handling is very one of basic skills in the printer involved technology, so if
paper is passing through the image creation units as designed, the output should be perfect.
However, if anything unexpected happens in the printer, this problem occurs.
It is said that skewing print image has mainly 3 kinds of causes.
The first one is related to the skewed image creation. And the second one is timing issues during the image
creation process and the last one is from unique paper attributes.
Among them, skewed image creation in the devices is not so common in the field because almost every
case is filtered during the manufacturing process, and none of device with the fault will be shipped out.
The second one is most frequently reported cases in the field, and a few factors that break the timing of
paper proceeding is the cause of this problem. It is recommended that the replacement of parts in the
paper path will remove most of this problem.
The last one is from unique paper attributes. There are huge number of paper brand in the world and none
of printer manufacturers can test and verify all of them. So we can encounter any unique kind of paper at
any time in the market, so we should need to deal with it on a case-by-case basis.

59 / 87
8) dots- spots

A dictionary says that DOT is a small SPOT, and on the contrary, SPOT is a large DOT.
Actually DOTs and SPOTs look very alike on the print image, so it seems to depend on the reporter’s
judgement.
This problem occurs during developing process or image transferring process and in the most typical office
environments, we can hardly see this.
When we encounter this problem in the market, it is recommended that we should see first if there is any
repetitive patterns of dots or spots on the image. If we can find the repetitive patterns, measure the period
of the repetitive images, and look at the related unit first. Mostly it is connected to the period of DRUM.
If there is no repetitive patterns of dots or spots, we can think other conditions as causes.
In this case, it is very likely to be related with T1 bias(voltage), T2 bias(voltage), high resistance paper, low
humidity environment and so on. The specific cause is depending on each case.
Sometimes this problem can be caused by the toner stored in inappropriate conditions before installation,
and when you see this case, you have to make sure that our assumption is correct.

60 / 87
9) blank pages

As you can imagine, blank page output means one or more of image generating parts are not fully
operational.
In fact, if something doesn’t work out completely, it’s not that hard to find it. We can check each image
generation step in order and narrow the cause of the problem.
This is very different from faded-color images, and when we found faded-color images on the output, at
least certain images were generated during the process. But this problem is different.
In the end, we can think the cause will be in the electrophotographic process. In short, we can focus on
LSU(Laser Scanning Unit) or HVPS(High Voltage Power Supply) for developer unit as a cause.
With low probability, firmware used to cause this problem.

61 / 87
10) ghosting
Printer ghosting literally stands for additional images around the original image, which is supposed to be
a single image. When we find this problem in the market, this is very confusing.
However, this ghosting print is mainly from the image generating parts such as drum, fuser, retransferring
roller and etc, so we don’t need to worry too much.
At first, if there is any repetitive rules of length about the additional ghost images, pick up the length and
compare it with the cycle of rotating parts within the paper path. This method allows you to find some
suspicious part which is corresponding that length.
If you fail to find the corresponding part of the ghosting print, check the image generating parts. As a good
way to find the cause, you can look at the state of the parts in the middle of image generation process.
The moment the device outputs the ghosting prints, you can find the cause by investigating this with a
high probability.
This problem is mainly caused by drum unit, fuser, retransferring roller, and sometimes unique paper types
and user environments create this problem.

62 / 87
[ Scan Quality ]

1) line - stripes / ADF lines

As we can image, lines on the images are the most frequent problem among the scan quality problems.
However, this is not a big deal because the scan device is less complex than print engine, and in fact, about
flatbed scanning, we can see all the scan process directly, so it is not a big problem to find the cause of
this problem.
Mainly scan quality problem occurs frequently on the ADF unit, and it is recommended to focus on the
operation of ADF unit. The most important part of scanning on ADF unit is the moment of reading document
with CCD module or CIS unit. If there is no issue with the scan at this point, most images are good and
they are not the cause of the lines on the scan image. Then we can move to other components such as
Main PCA or scan joint PCA as a cause of this problem.

63 / 87
2) blank pages

Blank page is one of common problems with the scan issues.

If the user obtains blank pages as outputs at the time of scanning, it is very likely to be the results of
malfunction of image processing IC which is commonly called CCD(Charge Coupled Device) IC or
AFE(Analog Front End) IC.
And if testing finds that the image processing IC is not the cause of this problem, it is advisable to look at
the physical passage of signal transmission, such as harnesses, flexible flat cables(FFCs). The wire states
between those units are very important and must be clearly verified.

64 / 87
 3) Skew

Skewed images in scanning are one of the problems that are very commonly reported to GBU.
It usually occurs a lot, but some of them are not easily resolved by immediate investigation or quick search
on site. So, when the problem is elevated to a high level of tech support or GBU, it is also one of the tricky
issues for the high level tech support team, too.
At this moment, we need to find how much the images were skewed compared to normal outputs, and we
need to collect clear information to show the state.
If I speak about the methods specifically, the official hard copy chart for technical service purposes is the
most recommended tools and by using it, on site engineers should get specific data showing the state in the
customer device.
Sometimes there is an argument about the tolerance of skewed images between a customer and technical
support team. It is when the technical support team judges the customer’s scan images are within the normal
tolerance margin, while the customers disagree and think the scan images are skewed beyond the tolerance.
When GBU team encountered this kind of case, the team investigated the case thoroughly, and used to
change the design within the limit of product specifications. However, fortunately most of cases were caused
by customer misunderstandings, and GBU team solved the cases with detailed guidance on the scan function.

65 / 87
4) light- faded

<Welcome to your tips and advice>

66 / 87
5) black pages

<Welcome to your tips and advice>

67 / 87
2. Sudden Impact cases

Case No. 1
Sudden SIE233881 - AU/E77830/Print Quality issue/ Wrong colour, red came out
Impact ID as orange

Symptom Colors of the original do not match the printed page when using an
Adobe application

Images

Solution a. Step one: Run the process to cancel the Auto Color Balance and
Setting Standard Tone settings
b. Step two: Set up the color tone to the factory default setting in the
Setting Standard Tone and Auto Tone Adjustment settings
c. Step three: Adjust the settings in Adobe Reader and in the Universal
Print Driver (UPD)

Affected HP Color LaserJet Managed MFP E77422-E77428, E78223-E78228

products HP Color LaserJet Managed MFP E77822-E77830, E78323-E78330
HP Color LaserJet Managed MFP E87640-E87660

Related c06591001
documents

68 / 87
Case No. 2
Sudden SIE231005 - Powerpoint color gradient printing
Impact ID
Symptom Color gradient printing quality is poor

Images

Solution • Adjust “Color Theme” to Photo SRGB on the driver

• Color > Color theme > Color Theme, RGB Color > Select Photo(sRGB)
(uncheck “HP Easy Color”)

Affected HP Color LaserJet, HP OfficeJet Enterprise Color, HP PageWide Enterprise

products Color

Related ish_2857290-2886150-16
documents

69 / 87
Case No. 3
Sudden SIE237183 - E87660z -image position problem- Cuts off margins when
Impact ID they Scan (Even to USB)
Symptom When they Scan it comes up skewed and cuts off left margin This issue
seems to be happening only when they Scan (even to USB) but does
not happen when they Copy.
Images

Solution
Image position alignment and Scanner hinge position set to 0.
Calibration performed automatic and manual .CE have tested well
the machine and performs great

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

70 / 87
Case No. 4
Sudden SIE232561 - E876 2mm image stretch when compared to other
Impact ID Gemstones
Symptom 11x17 prints are getting stretched in feed the direction approx 2 mils
longer on the E876 as compared to the E778.
Images

Solution
4.11 FW has solution for this.

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

71 / 87
Case No. 5
Sudden SIE227548 - Front side of duplex print image defect
Impact ID
Symptom When duplex print high coverage blocks the odd pages of the print
have shadowing around the print
Images

Solution
Adjust T2 value in T2 control mode (Service mode)

• SIMPEX : -1 or -2 (Actually, this value is not related with this

issue.)

• DUPLEX : +6

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

72 / 87
Case No. 6
Sudden SIE228148 - Image cropped when print a power point slide from Mac
Impact ID OS 10.14 with PPD of E87640
Symptom Customer reported that PPT image was cropped when customer
printed a specific file. We could reproduce here.
Images

<Cropped image> <Good image>

Solution
Fixed with FS 5.1

- Mac OS: 10.14.6

- PPD Name/Version: HP Color MFP E87640-50-60 /19.3000
(Downloaded via HP Easy Start)
- MS PowerPoint version: 15.14(150911)
- FW version: FS 4.7.3.1

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

73 / 87
Case No. 7
Sudden SIE257692 - E87660-KPMG LLC/ PQ white or dark lines
Impact ID
Symptom Diagonal lines marks on Magenta
Images

Solution
Issue resolved with toner replenishment and calibration procedure
provided.

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

74 / 87
Case No. 8
Sudden SIE262736 - Scan / copy job output is blank paper (with some black lines)
Impact ID
Symptom copy output is blank paper
Images
ADF Platen

Solution Whole Unit Replacement(WUR)

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

75 / 87
Case No. 9
Sudden SIE190916 - Bandings on print out .
Impact ID
Symptom The customer prints a PowerPoint slide with full green solid colour and there are
bandings appearing on the printout.
Images

Solution
drums were out of spec for runout. So it Replaced the drums.

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
document
s

76 / 87
Case No. 10
Sudden SIE267155 - E87660 series/ PQ defect - Intermittent Poor Fusing Issue
Impact ID
Symptom Printer reported as image not bond properly (Poor Fusing) especially to
the colour printed.
Images

Solution
found out cust been using non HP toner which cause the bonding
issue

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

77 / 87
Case No. 11
Sudden SIE214260 - AU/E77822/This Jade unit produced blank page with 1cm
Impact ID of multi colour line from top to bottom at the edge of the page on the
right side when scan from flatbed scanner or ADF through slit glass;
Symptom Jade unit produced blank page with 1cm of multi colour line appear from
top to bottom at the edge of the page on the right hand side when
scan/copy from flatbed scanner or ADF through slit glass.

Duplex scan through ADF - backside scan ok but frontside scan blank
with 1cm multi colour line on the right.

Flatbed scan - blank page with with 1cm multi colour line on the right.
Images

Solution
Resolved by replacing whole scanner assy.

Affected
products HP Color LaserJet Managed Flow MFP E77822-E77830z
Related -
documents

78 / 87
Case No. 12
Sudden SIE231848 - E825 lines on scans
Impact ID
Symptom Lines on the scans + Original size reduced about 20%
Images

Solution
- replaced Main PCA and HDD

- uploaded latest firmware performed scanner adjustments

Affected HP LaserJet Managed Flow MFP E82540-E82560z

products
Related -
documents

79 / 87
Case No. 13
Sudden SIE249649 – E778-copy quality – when using the ADF it skews the output
Impact ID
Symptom When performing copies the output will come out skewed
Images

Solution
Problem resolved with correct height hinge adjustments and ADF
calibration and adjustments.

Affected
products HP Color LaserJet Managed Flow MFP E77822-E77830z
Related -
documents

80 / 87
Case No. 14
Sudden SIE234739 - AU/ Ruby/E87660z/ 12 units - skew on A3 when scan. Skew
Impact ID from front side scanner
Symptom The outer of the copy is cropped and skew.
Images

Solution <How to adjust print skew>

1) Service tools > Service > Pin code (04087617: E876xx) > Service
tools > Diagnostics > Adjustment > Buckle adjustment

2) Set up the following options (We have to adjust both ‘on’ and ‘off’
on Fast feed )

A. Fast feed “off” / Print side “Duplex” /Regi curl “+1” for A4 LEF
duplex printing

B. Fast feed “on” / Print side “Duplex” /Regi curl “+1” for A4 SEF and
A3 duplex printing

3) Do this again until the print images look fine, then print out some
images and look at the skew on them before leaving the site
Affected HP Color LaserJet Managed MFP E87640-E87660
products
Related -
documents

81 / 87
Case No. 15
Sudden SIE262969 - Blank printout with one black band while making copy from
Impact ID DADF and platen glass.
Symptom one black band while making copy from DADF and platen glass.
Images

Solution
replacing the following part ( 4Pin -FFC cable)

JC39-02120A --- FLAT CABLE-WLED,X4300,4P,420,A forTopaz

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

82 / 87
Case No. 16
Sudden SIE212595 - First side copy black - found damaged FFC for scanner lamp
Impact ID
Symptom
First side copy black - found damaged FFC for scanner lamp

Images

Solution
Scanner assembly replaced due to a faulty FFC cable to scan head
found.

Affected HP Color LaserJet Managed MFP E87640-E87660

products
Related -
documents

83 / 87
Case No. 17
Sudden SIE227548
Impact ID
Symptom When duplex print high coverage blocks the odd pages of the print have
shadowing around the print
Images

Solution Solved by changing the configuration (includes swapping hardware and

modifying tuning parameters)
If the contrast is high, the shadows in the text disappear.

Affected HP LaserJet Managed Flow MFP E72525-E72535z

products
Related
documents

84 / 87
Case No. 18
Sudden SIE197309
Impact ID
Symptom Image being clipped at edges when copying

Images x

Solution Provided guide to adjust the image.

Affected HP Color LaserJet Managed Flow MFP E87650z - Speed 50 ppm

products
Related
documents Adjusting the
image registration o

85 / 87
Case No. 19
Sudden SIE263144
Impact ID
Symptom Image shift in copy and scan quality. Scan area adjustment and Copy
manual adjustment has been failing
Images

Solution Replacing ADF

Affected HP LaserJet Managed MFP E72525dn Plus

products
Related
documents

86 / 87
- End of document -

87 / 87