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HP LaserJet 6p/mp Service Manual - Page 131

Background scatter, Black Dropouts, Half of the Is blank or loss of detail - memory install

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Background scatter Background scatter results from bits of toner distributed on the front or back of a printed page. Background scatter often is isolated to a specific area of the page. l Check the environment. High humidity can cause this error. l Change the paper type, weight, or surface finish. See appendix B of the User's Manual for paper specifications. l If background scatter occurs on an envelope, try moving the text to an area with no seams. Printing on seams can cause this problem. l If background scatter covers the entire surface of an envelope, try adjusting the print density through your software or printer driver. l If this problem occurs on the back of a printed page, it may be caused by spilled toner inside the printer. See "Cleaning Your Printer" in Chapter 4. Black page A page is completely black. l The toner cartridge may not be installed properly. Remove the cartridge and reinsert it. l The toner cartridge may be defective. Replace it. l There may be discontinuities in the high-voltage contact points. Clean the high voltage contact points on the toner cartridge and transfer roller. (See Figures 7-5 and 7-6.) l Replace the DC Controller or Laser/Scanner unit. Dropouts Dropouts are characters that are partially printed. l The Paper Input Tray may have been loaded with too much paper. Make sure that no more than 100 sheets of paper are loaded. l A single sheet of paper may be defective. Try reprinting the job. l Try adjusting the print density through your software or printer driver. l Try cleaning the rollers. l The moisture content of the paper may be inconsistent, or the paper may have moist or wet spots on the surface. Try paper from a fresh ream or a different paper manufacturer. l The paper may have been damaged by inconsistent manufacturing processes. Try paper from a different source. Half of the page Is blank or loss of detail The bottom of the page is blank, or part of a graphics image is cut off. This may mean that your page is too complex for the standard printer memory. l Set resolution to 300 dpi through your software or printer driver. l You may need to install additional memory in your printer. See Chapter 6 for memory installation instructions. l Check your printer driver help screens for suggestions specific to your driver's settings. EN Image formation troubleshooting 129

Section	Page
Contents	7
Figures	11
Tables	13
Product information	15
Chapter contents	15
Printer features	16
Identification	17
HP LaserJet 6L Gold	17
Model and serial	17
Specifications	20
Product overview	21
Service approach	24
Parts Exchange Program	24
Ordering parts	24
Ordering related documentation	24
Contacting HP to place an order	24
Technical assistance	25
HPCustomer Care	25
HP worldwide sales and service offices	27
Warranty	30
Hardware service during the warranty period	30
Hardware service after the warranty period	30
HP LaserJet Toner Cartridge warranty	31
Voltage conversions	31
Site requirements	33
Chapter contents	33
Site requirements	34
Operating environment	34
Printer space requirements	35
The HP C3906A/F Toner Cartridge	36
Storage conditions	36
Storing opened toner cartridges	36
Toner cartridge handling suggestions	37
Operating overview	39
Chapter contents	39
Using the Control Panel	40
Control Panel layout	40
Indicator lights	40
The Control Panel Button	42
Printing a self-test page	43
Continuous self test	46
Printing an engine test	46
Resetting the printer	47
To reset the printer	47
Printer maintenance	49
Chapter contents	49
Life expectancy of consumables	50
Toner cartridge life	51
Saving toner with EconoMode	51
Refilled toner cartridges	52
Recycling toner cartridges	52
Cleaning the printer	53
Cleaning printer components	53
Cleaning spilled toner	54
Functional overview	55
Chapter contents	55
Basic printer functions	56
DC Controller/power system	57
Print engine control system	58
Power system (on DC Controller PCA)	58
Formatter system	60
CPU	60
Read only memory (ROM)	60
Random access memory (RAM)	60
Parallel interface	60
Control Panel	60
Resolution Enhancement technology (REt)	61
EconoMode	61
Memory Enhancement technology (MEt)	61
Enhanced I/O	61
Page Protect	62
PJL overview	62
Image formation system	63
Toner cartridge	63
Step 1: Drum cleaning	64
Step 2: Drum conditioning	64
Step 3: Image writing	64
Step 4: Image developing	64
Step 5: Image transferring	64
Step 6: Image fusing	64
Paper feed system	65
Paper jam detection	67
Basic sequence of operation	68
Removal and replacement	71
Chapter contents	71
Removal and replacement strategy	72
Required tools	73
Installing memory cards (DRAM)	74
Covers and doors	75
Back Cover	75
EP Door Assembly	77
Memory Door	78
Main Cover and Paper Input Assembly	79
Internal assemblies	80
Control Panel	80
Exit Roller Assembly	81
Delivery Assembly	82
Fuser Pressure Plate	84
Heating Element	86
Pressure Roller	89
Face-Up/Face-Down Lever	90
Fuser Exit Roller Assembly	91
Paper Exit Sensor Flag	92
Top assemblies	93
Laser/Scanner Assembly	93
Solenoid	94
Pickup Roller Assembly	96
Paper Feed Frame	99
Transfer Roller Guide and Transfer Roller	103
Kick Plate	104
Separation Pad	106
Subpads	107
Feed Assembly	108
Bottom assemblies	111
Memory Door Guide	111
Motor	112
DC Controller	113
Formatter PCA	116
Troubleshooting	117
Chapter contents	117
General troubleshooting flowchart	118
Paper path and components	120
DC Controller diagram	121
Printer error troubleshooting	122
Priority of errors	122
Printer status messages	123
Service and error messages	125
Image formation troubleshooting	128
Check the toner cartridge	128
Image defect examples	129
Troubleshooting checks	135
Engine test	135
Half self-test functional check	136
Drum rotation functional check	136
High-voltage power supply check	137
Paper curl	139
Troubleshooting tools	140
Paper path check	140
Repetitive image defect ruler	141
Main wiring diagram	142
Parts and diagrams	145
Chapter contents	145
How to use the part lists and diagrams	146
Ordering parts	146
Ordering consumables	146
Accessories and supplies	147
Common hardware	148
Parts diagrams	149
Parts index	169
Alphabetical parts list	169
Numerical parts list	174
Regulatory information	179
Laser Safety (U.S.)	179
Laser Statement (Finland)	180
Toner safety	181
Ozone emission	181
FCC Statement (Class B)	182
VCCI Statement (Japan)	182

Match case Limit results 1 per page

Image formation troubleshooting

129

Background scatter

Background scatter results from bits of toner distributed on the front or back

of a printed page. Background scatter often is isolated to a specific area of

the page.

Check the environment. High humidity can cause this error.

Change the paper type, weight, or surface finish. See appendix B of the

User’s Manual for paper specifications.

If background scatter occurs on an envelope, try moving the text to an

area with no seams. Printing on seams can cause this problem.

If background scatter covers the entire surface of an envelope, try

adjusting the print density through your software or printer driver.

If this problem occurs on the back of a printed page, it may be caused by

spilled toner inside the printer. See “Cleaning Your Printer” in Chapter 4.

Black page

A page is completely black.

The toner cartridge may not be installed properly. Remove the cartridge

and reinsert it.

The toner cartridge may be defective. Replace it.

There may be discontinuities in the high-voltage contact points. Clean

the high voltage contact points on the toner cartridge and transfer roller.

(See Figures 7-5 and 7-6.)

Replace the DC Controller or Laser/Scanner unit.

Dropouts

Dropouts are characters that are partially printed.

The Paper Input Tray may have been loaded with too much paper. Make

sure that no more than 100 sheets of paper are loaded.

A single sheet of paper may be defective. Try reprinting the job.

Try adjusting the print density through your software or printer driver.

Try cleaning the rollers.

The moisture content of the paper may be inconsistent, or the paper may

have moist or wet spots on the surface. Try paper from a fresh ream or a

different paper manufacturer.

The paper may have been damaged by inconsistent manufacturing

processes. Try paper from a different source.

Half of the page Is blank or loss of detail

The bottom of the page is blank, or part of a graphics image is cut off. This

may mean that your page is too complex for the standard printer memory.

Set resolution to 300 dpi through your software or printer driver.

You may need to install additional memory in your printer. See Chapter 6

for memory installation instructions.

Check your printer driver help screens for suggestions specific to your

driver’s settings.