HP Laserjet 5 Service Manual

EconoMode
The EconoMode setting uses approximately 50% less toner than standard mode
printing by reducing the dot density. However, EconoMode does not extend toner
cartridge component life. EconoMode, which can also be thought of as “draft
mode,” is user-selectable through some software applications. The default setting is
Off.
EconoMode vs Normal Mode
NoteEconoMode does not affect print speed or memory usage.
Memory Enhancement technology (MEt)
The Hewlett-Packard Memory Enhancement technology (Met)...

Enhanced I/O
The Enhanced I/O feature allows printer memory to be used for storing data
received from the host computer. When Enhanced I/O is enabled, you can send
more data to your printer in shorter amounts of time, which allows you to return to
your application sooner. Enhanced I/O has the following options:
·Auto—allows the printer to use Enhanced I/O memory allocation to increase the
speed of data transfer from the host computer to the printer, if necessary.
·Off—uses the minimum amount of printer...

Image Formation System
Laser printing requires the interaction of several different technologies (such as
electronics, optics, and electrophotographics) to provide a printed page. Each
process functions independently and must be coordinated with the other printer
processes. Image formation consists of six processes:
·Step 1. Drum Cleaning
·Step 2. Drum Conditioning
·Step 3. Image Writing
·Step 4. Image Developing
·Step 5. Image Transferring
·Step 6. Image Fusing
Image Formation Block Diagram
2. Scanning...

Toner Cartridge
As the “heart” of the Image Formation System, the toner cartridge houses the
cleaning, conditioning, and developing steps of the process. The toner cartridge
contains the photosensitive drum, primary charging roller, developing station, toner
cavity, and cleaning station. Including these components, which wear, degrade, or
are consumed in the replaceable toner cartridge, eliminates the need for a service
call when replacement is required. The special photosensitive properties of the drum...

Step 4: Image Developing
At this stage of the process, the latent electrostatic image is present on the drum.
The toner particles obtain a negative surface charge by rubbing against the
developing cylinder which is connected to a negative DC supply. The negatively
charged toner is attracted to the discharged (exposed, grounded) areas of the drum,
and repelled from the negatively charged (non-exposed) areas.
Step 5: Image Transferring
During the transferring process, the toner image on the drum surface is...

Paper Feed System
Both the Paper Input Bin and the Single Sheet Input Slot merge into one, main input
area. Paper placed in either of these areas enables the Paper Out Sensor (sensor
202), which informs the DC Controller that paper is present.
When the printer receives a print job and is ready to print, the DC Controller
enables the Laser/Scanner Assembly and the Motor. Paper motion begins when the
DC Controller energizes solenoid SL1. This causes the paper pick up roller to rotate
once. Two actions...

Figure 5-5 shows a simplified paper path and the locations of the photosensors and
rollers.
Simplified Paper Path
Figure 5-5
5 - 16 Functional Overview 

Figure 5-6 shows the locations of the photosensors, switches, solenoid, and other
important printer elements. Table 5-1 describes the function of each photosensor
and the solenoid.
Solenoid and Sensors
Figure 5-6
No. Name Description
SL1 Paper Pick-up Solenoid Enables the Paper Pickup Roller.
PS201 Paper Exit Sensor Senses when paper has successfully moved out of the
fusing area and the next sheet of paper can be fed.
PS202 Paper Out Sensor Senses no paper in either the Paper Input Bin or Manual
Input...

Paper Jam Detection
The Paper Out Sensor (PS202), Paper Registration Sensor (PS203), and the Paper
Exit Sensor (PS201) detect when paper is moving through the printer. (See Figure
5-5 for roller and sensor locations.) If a paper jam is detected, the DC Controller
immediately stops the printing process and causes a paper jam indication on the
front panel.
A paper jam can be detected under any of the following conditions:
·Power-On Jams.Paper is present under either PS201 or PS203 at power-on.
·Pickup...

Basic Sequence of Operation
The Formatter PCA and the DC Controller PCA share information during printer
operation. The DC Controller-to-Formatter Connector (J201) forms a link which
operates as a serial data bus. This allows printer status, command information, and
dot-image data to be passed between the two PCAs. Figure 5-7 shows the general
timing of the printer events. The following events take place during normal printer
operation:
Period Timing Purpose
WAIT From when the paper is inserted to the...