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HP 2700n Service Manual - Page 103

Latent-image formation stage, Step 1: pre-exposure, Step 2: primary charging

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Latent-image formation stage During the three steps that comprise this stage, a latent image is formed by applying a negative charge to the photosensitive drum. You cannot see this image on the drum. Step 1: pre-exposure The pre-exposure LED hits the photosensitive drum surface and eliminates any residual charge on the surface. Figure 4-11 Pre-exposure Step 2: primary charging A high-voltage dc bias is applied to the primary charging roller, which is made of conductive rubber and is in contact with the drum surface. As the roller moves across the drum, it applies the negative charge to that surface. Step 3: laser-beam exposure The laser beam scans the photosensitive drum to neutralize the negative charge on portions of the drum surface. An electrostatic latent image is formed where the negative charge was neutralized. Figure 4-12 Laser-beam exposure Developing stage The developing cylinder comes in contact with the photosensitive drum and deposits toner on the electrostatic latent image. ENWW Image-formation system 85

Section	Page
Product information	19
Printers at a glance	20
Features at a glance	21
Walkaround	22
Understanding control-panel features	24
Using the control-panel menus	25
To use the menus	25
Reports menu	26
System Setup menu	27
Network Config. menu (HP Color LaserJet 2700n printer only)	29
Service menu	30
Printer software	31
Supported operating systems and printer drivers	31
Additional drivers	31
Opening the printer drivers	32
Software for Windows	33
The HP ToolboxFX	33
Software for Macintosh	33
PostScript Printer Description (PPD) files	33
Macintosh Configure Device	33
Software for networks	34
HP Web Jetadmin	34
UNIX	34
Linux	34
Embedded Web server	34
Print-media specifications	35
Tray 1 and tray 2	35
Optional tray 3	36
Selecting print media	37
Paper to avoid	37
Paper that can damage the printer	37
Printing and storage environment	38
Printing on special media	39
Transparencies	39
Glossy paper	39
Colored paper	39
Envelopes	39
Labels	40
Heavy paper	40
Preprinted forms and letterhead	40
Recycled paper	41
HP LaserJet media	41
Installation and configuration	43
What is in the box	44
Site requirements	45
Physical specifications	45
Configuring trays	46
Configuring size	46
Configuring type	46
Configuring trays for custom paper	46
Printing from tray 1 (100-sheet multipurpose tray)	46
Loading tray 1	46
Printing from tray 2 or optional tray 3	48
Loading tray 2	49
Loading optional tray 3	51
Loading special media	54
USB configuration	55
Connecting the USB cable	55
Network configuration (HP Color LaserJet 2700n only)	56
Set up the printer and use it on the network	56
To set up a network port-connected configuration (direct mode or peer-to-peer printing)	56
Using the embedded Web server or the HP ToolboxFX	57
Setting a system password	57
Using the printer control panel	57
IP configuration	57
Manual configuration	57
Automatic configuration	58
Link speed and link duplex settings	58
Supported network protocols	59
TCP/IP	60
Internet Protocol (IP)	60
Transmission Control Protocol (TCP)	60
IP address	60
Configuring IP parameters	60
Dynamic Host Configuration Protocol (DHCP)	61
BOOTP	61
Subnets	61
Subnet mask	61
Gateways	61
Default gateway	61
Printer memory	62
Installing memory DIMMs	62
To install memory and font DIMMs	62
Enabling memory	65
To enable memory for Windows	65
Checking DIMM installation	65
To check DIMM installation	65
Maintenance	67
Managing supplies	68
Supplies life	68
Approximate print-cartridge replacement intervals	68
Checking the print-cartridge life	68
Print-cartridge storage	69
HP print cartridges	69
Non-HP print cartridges	69
Print-cartridge authentication	69
HP fraud hotline and Web site	70
Replacing supplies and parts	71
Supply replacement guidelines	71
Changing print cartridges	71
To change the print cartridge	71
Cleaning the printer	74
To clean the printer using the printer control panel	74
To clean the printer using the HP ToolboxFX	74
Calibrating the printer	75
Tools for managing the printer	76
Using printer information pages	76
Using the embedded Web server	77
To access the embedded Web server by using a network connection	78
Embedded Web server sections	79
Using the HP ToolboxFX	80
To view the HP ToolboxFX	81
Status	82
Event log	82
Alerts	83
Set up status alerts	83
Set up e-mail alerts	83
Help	83
Device settings	84
Device information	84
Paper handling	85
Printing	85
PCL5c	85
PostScript	85
Print quality	86
Print density	86
Paper types	86
System setup	87
Service	87
Network settings	87
Using Macintosh Configure Device	87
Theory of operation	89
Engine control system	90
Power-on sequence	91
Motors, fans, and solenoids	92
Laser/scanner system	93
Pickup-and-feed-system	94
Sensors in the pickup-and-feed system trays (cassettes)	94
Cassette pickup mechanism	96
Multipurpose-tray pickup mechanism	96
Feed-speed control	98
Sensor jam detection	99
Image-formation system	101
Image-formation process	102
Latent-image formation stage	103
Step 1: pre-exposure	103
Step 2: primary charging	103
Step 3: laser-beam exposure	103
Developing stage	103
Step 4: developing	104
Transfer stage	104
Step 5: media feed	104
Step 6: image transfer	104
Step 7: separation from the drum	105
Step 8: separation from the ETB	105
Fusing stage	105
Step 9: fusing	105
Cleaning stage	106
Step 10: drum cleaning	106
Print cartridge	106
Print-cartridge activation	107
Removal and replacement	109
Removal and replacement strategy	110
Introduction	110
Required tools	111
Types of screws	112
Service approach	113
Before performing service	113
After performing service	113
Print cartridges	114
External doors, covers, and panels	115
Front cover	115
Upper cover (fuser door)	118
Rear lower cover	121
Left cover	122
Right cover	125
Rear upper cover	129
Internal assemblies	130
Formatter cage	130
Electrostatic transfer belt (ETB)	132
Fuser	133
Print-cartridge drive motors	134
Fuser drive assembly	135
Developing separation-drive assembly	137
Pickup-and-feed assembly	142
Pickup-drive assembly	147
Laser/scanner assembly	156
Main fan	160
Printed circuit assemblies (PCAs)	162
Low-voltage power-supply PCA	162
DC controller PCA	166
High-voltage power supply	168
Memory-controller PCA	170
Driver PCA	172
Control panel	174
Pickup-and-feed driver (relay) PCA	176
Sensors	178
Temperature sensor	178
Paper and registration sensor covers	179
Cartridge-sensor PCA	180
500-sheet feeder	183
500-sheet feeder right cover	183
500-sheet feeder left cover	185
500-sheet feeder rear cover	188
500-sheet feeder driver PCA	190
Troubleshooting	193
Troubleshooting process	194
Pre-troubleshooting checklist	194
Troubleshooting flowchart	196
Power-on checks	197
Control-panel messages	198
Event-log messages	211
Jams	212
Common causes of jams	212
Clearing jams	213
Image defects	225
Light image	226
Light color	226
Dark image	227
Dark color	227
Completely blank image	228
All black or solid color	228
Dots in vertical lines	228
Dirt on back of paper	228
Dirt on front of paper	229
Vertical lines	229
White vertical lines	229
Horizontal line	230
White horizontal line	230
Color missing	231
Blank spots	231
Poor fusing	231
Image distortion	232
Color misregistration	232
Smearing	233
Misplaced image	233
Reversed color	233
Snail tracks	233
Repetitive-defects troubleshooting	234
Interface troubleshooting	236
Communication checks	236
EIO troubleshooting	236
Secondary service menu	237
Open the secondary service menu	237
Secondary service menu structure	237
Test pages	239
Engine test page	239
Formatter test	239
Half-self test	239
Drum-rotation test	240
Engine resets	241
Engine resets	241
Restore defaults (cold reset)	241
NVRAM initialization	241
Configuration utility	242
Troubleshooting diagrams	243
Connector locations	243
Major assemblies	245
DC controller connectors	249
Timing diagram	250
Circuit diagrams	251
Parts and diagrams	255
Ordering parts and supplies	256
Parts	256
How to use the parts lists and diagrams	256
Types of screws	256
Related documentation and software	257
Accessories and supplies	257
External panels and covers	260
Internal components	266
Paper-pickup drive assembly	276
Developing separation-drive assembly	278
Fuser drive assembly	280
Cassette (tray 2)	282
Paper-pickup assembly	284
Electrostatic transfer belt	286
Multipurpose tray assembly (tray 1)	288
Fuser	290
PCAs	292
500-sheet feeder cassette (tray 3)	294
500-sheet feeder paper-pickup assembly	296
500-sheet feeder PCA	298
Alphabetical parts list	300
Numerical parts list	308
Printer specifications	317
Physical specifications	318
Electrical specifications	319
Acoustic emissions	320
Operating-environment specifications	321
Service and support	323
Hewlett-Packard limited warranty statement	324
Print cartridge limited warranty statement	325
HP Customer Care	326
Online Services	326
Telephone support	326
Software utilities, drivers, and electronic information	326
HP direct ordering for accessories or supplies	326
HP service information	326
HP service agreements	326
The HP ToolboxFX	327
HP support and information for Macintosh computers	327
HP maintenance agreements	328
On-site service agreements	328
Next-day on-site service	328
Weekly (volume) on-site service	328
Extended warranty	328
Repacking the printer	329
Regulatory information	331
FCC regulations	332
Environmental product stewardship program	333
Protecting the environment	333
Ozone production	333
Power consumption	333
Paper use	333
Plastics	333
HP LaserJet printing supplies	333
HP printing supplies returns and recycling program information	333
Paper	334
Material restrictions	334
Disposal of waste equipment by users in private households in the European Union	334
Material Safety Data Sheet (MSDS)	334
Extended warranty	334
For more information	335
Declaration of conformity	336
Safety statements	337
Laser safety	337
Canadian DOC regulations	337
EMI statement (Korea)	337
VCCI statement (Japan)	337
Power cord statement (Japan)	337
Laser statement for Finland	338

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Latent-image formation stage

During the three steps that comprise this stage, a latent image is formed by applying a negative charge

to the photosensitive drum. You cannot see this image on the drum.

Step 1: pre-exposure

The pre-exposure LED hits the photosensitive drum surface and eliminates any residual charge on the

surface.

Figure 4-11

Pre-exposure

Step 2: primary charging

A high-voltage dc bias is applied to the primary charging roller, which is made of conductive rubber and

is in contact with the drum surface. As the roller moves across the drum, it applies the negative charge

to that surface.

Step 3: laser-beam exposure

The laser beam scans the photosensitive drum to neutralize the negative charge on portions of the drum

surface. An electrostatic latent image is formed where the negative charge was neutralized.

Figure 4-12

Laser-beam exposure

Developing stage

The developing cylinder comes in contact with the photosensitive drum and deposits toner on the

electrostatic latent image.

ENWW

Image-formation system