HP P 1100 Service Manual

							Sequence of operation
The DC controller in the engine-control system controls the operational sequences of the product. The
table below describes durations and operations for each period of a print operation from when the
prroduct is turned on until the motor stops rotating.
Normal sequence of operation
Table 1-1  Sequence of operation
NameTimingPurpose
WAITFrom the time the power switch is turned on, the door
is closed or the product exits Sleep mode until the
product gets ready for a print operation.Brings the product to the ready state. The product
performs the following during the operations:
●Detects the print cartridge
● Heats the fuser film in the fuser
● Rotates, and then stops, the main motor
STBY (standby)From the end of the WAIT or LSTR period until either
a print command is sent or the power switch is turned
off.Maintains the product in printable condition. The
product performs the following during the operation:
●Enters Auto-Off mode if the Auto-Off command
is received
INTR (initial
rotation)From the time a print command is received until the
paper is picked up.The product performs the following during the
operations:
●Drives the main motor
● Activates the high-voltage power supply
● Activates the laser/scanner
● Warms the fuser heater
PRINTFrom the end of the INTR period until the last sheet
completes the fuser operation.Forms the image on the photosensitive drum based
on the VIDEO signals from the formatter. Transfers
and fuses the toner image to the paper.
LSTR (last
rotation) From the end of the PRINT period until the main motor
stops rotating. Moves the last printed sheet out of the product. The
product performs the following during the operations:
●
Stops the main motor
● Deactivates the high-voltage power supply
● Deactivates the laser/scanner
● Deactivates the fuser heater
The product enters the INTR period as the LSTR
period is completed, if the formatter sends another
print command.
ENWW Basic operation 3 
						

							Formatter-control system
The formatter is responsible for the following procedures:
●Controlling sleep mode
● Receiving and processing print data from the various product interfaces
● Monitoring control-panel functions and relaying product-status information (through the control
panel and the network or bidirectional interface)
● Developing and coordinating data placement and timing with the DC controller PCA
● Storing font information
● Communicating with the host computer through the network or the bidirectional interface
The formatter receives a print job from the network or bidirectional interface and separates it into image
information and instructions that control the printing process. The DC controller PCA synchronizes the
image-formation system with the paper-input and -output systems, and then signals the formatter to
send the print-image data.
Sleep mode
NOTE: This product uses an Auto-Off feature for sleep mode.
After a user-specified time, the Auto-Off feature automatically conserves electricity by substantially
reducing power consumption when the product is not printing. After a user-specified time, the product
automatically reduces its power consumption (Auto-Off). The product returns to the ready state when a
button is pressed, a print job is received, or a door is opened. When the product is in Auto-Off mode,
the control-panel LEDs and the power button backlight LED are off.
NOTE:Although the product lights are off in Auto-Off mode, the product functions normally when it
receives a print job.
Input/output
The product receives print data primarily from the following:
● Hi-Speed USB 2.0 port
● 802.11b/g wireless networking (wireless models only)
CPU
The formatter incorporates a 400 MHz Helium processor.
Memory
The random access memory (RAM) on the formatter PCA contains the page, I/O buffers, and the font
storage area. RAM stores printing and font information received from the host system, and can also
serve to temporarily store a full page of print-image data before the data is sent to the print engine.
4 Chapter 1   Theory of operation ENWW 
						

							Firmware
●HP LaserJet Professional P1100 Printer series
◦The product has 2 MB of Synchronous DRAM, which is used for run-time firmware imaging
and specific print job information for the print job.
● HP LaserJet Professional P1100w Printer series
◦The product has 8 MB of Synchronous DRAM, which is used for run-time firmware imaging
and specific print job information for the print job.
Memory use
● HP LaserJet Professional P1100 Printer series
◦The product has a 2 KB EEPROM and 64 MB of NAND Flash Memory, which is used for
product configuration information and printer driver firmware.
● HP LaserJet Professional P1100w Printer series
◦The product has a 8 KB EEPROM and 64 MB of NAND Flash Memory, which is used for
product configuration information and printer driver firmware.
PJL overview
The printer job language (PJL) is an integral part of configuration, in addition to the standard printer
command language (PCL). With standard cabling, the product can use PJL to perform a variety of
functions such as these:
● Two-way communication with the host computer through a network connection or a USB
connection. The product can inform the host about such things as the control-panel settings, and
the control-panel settings can be changed from the host.
● Dynamic I/O switching. The product uses this switching to be configured with a host on each I/O.
The product can receive data from more than one I/O simultaneously, until the I/O buffer is full.
This can occur even when the product is offline.
● Context-sensitive switching. The product can automatically recognize the personality (PS or PCL)
of each job and configure itself to serve that personality.
● Isolation of print environment settings from one print job to the next. For example, if a print job is
sent to the product in landscape mode, the subsequent print jobs print in landscape mode only if
they are formatted for landscape printing.
LEDM overview
NOTE:
HP LaserJet Professional P1100w Printer series
The low-end data model (LEDM) provides one consistent data representation method and defines the
dynamic and capabilities tickets shared between clients and devices, as well as the access protocol,
event, security, and discovery methods.
ACL overview
The advanced control language (ACL) is a language that supports product control and firmware
downloads in products that support both PJL/PCL and host-based printing. Each sequence of ACL
ENWW Formatter-control system 5 
						

							commands must be preceded by a unified exit command (UEL) and an @PJL ENTER LANGUAGE=ACL
command. The ACL sequence is always followed by a UEL. Any number of commands can be placed
between the UELs. The only exception to these rules is the download command. If a firmware download
is done, the download command must be the last command in the sequence. It will not be followed by
a UEL.
The firmware searches for the UEL sequence when parsing commands. However, while downloading
binary data such as host-based code or NVRAM data the firmware suspends UEL parsing. To handle
hosts that “disappear” during binary sequences, the firmware times out all ACL command sessions. If
a timeout occurs during a non-download command sequence, it is treated as the receipt of a UEL. If a
timeout occurs during firmware download the product resets.
Control panel
The formatter sends and receives product status and command data to and from the control-panel PCA.
Wireless PCA
NOTE:Wireless models only.
The wireless PCA controls the wireless function of the product
6 Chapter 1   Theory of operation ENWW 
						

							Engine-control system
The engine-control system coordinates all product functions, according to commands that the formatter
sends. The engine-control system drives the laser/scanner system, the image-formation system, and
the pickup/feed/delivery system.
The engine control system contains the following major components:
●Engine-control unit (ECU)
◦DC controller
◦ Low-voltage power supply
● High-voltage power supply
● Fuser control
Figure 1-2   Engine-control system
MEDIA-FEED SYSTEM
ENGINE CONTROL SYSTEM
DC controller LASER/SCANNER SYSTEM
IMAGE-FORMATION SYSTEM
Formatter
High-voltage power supplyLow-voltage power supply
Fuser control
ENWW Engine-control system 7 
						

							Motors, fans, clutches, solenoids, switches, and sensors
Figure 1-3  Motors
M1
M2
Table 1-2  Motors
DescriptionComponents driven
Main motor (M1)●Pickup roller
● Feed roller
● Photosensitive drum
● Developing roller
● Pressure roller
● Delivery roller
Scanner motor (M2)●Scanner mirror
8 Chapter 1   Theory of operation
ENWW 
						

							Figure 1-4  Solenoids and clutches
SL1
Table 1-3  Solenoids and clutches
ItemDescription
SL1Pickup solenoid
Figure 1-5   Switches
Table 1-4  Switches
ItemDescription
SW501Cartridge-door switch
SW502Power switch; not shown
ENWW Engine-control system 9 
						

							Figure 1-6  Sensors
PS751
PS701
PS702
Single-sheet-feed slot
(HP LJP P1100w printer Series)
Table 1-5  Sensors
ItemDescription
PS701Fuser delivery sensor
PS702Media width sensor
PS751Top-of-Page (TOP) sensor
PS901Main-motor rotation-number sensor; not shown
10 Chapter 1   Theory of operation ENWW 
						

							DC controller operations
The DC controller controls the operational sequences of the product systems.
Figure 1-7  DC controller block diagram
Transfer roller Motor
Solenoid
Photointerrupter
Laser scanner
Formatter Switch
Operation panel Engine controller
Fuser unit
High-voltage
power supply
Cartridge AC input
Low-voltage
power supply
DC controller
Table 1-6  DC controller controlled components
ComponentDesignatorDescription
MotorM1Main motor
M2Scanner motor
SolenoidSL1Pickup solenoid
Photointerrupter PS701Fuser delivery sensor
PS702Media width sensor
PS751Top-of-Page (TOP) sensor
PS901Main-motor rotation-number sensor
ENWW Engine-control system 11 
						

							ComponentDesignatorDescription
SwitchSW501Cartridge-door switch
SW502Power switch
Fuser-control circuit
The fuser-control circuit monitors and controls the temperature in the fuser. The product uses on-
demand fusing. The fuser-control circuit consists of the following major components:
●Fuser heater (H1); heats the fusing film
● Thermistor (TH1); detects the fuser temperature (contact type)
● Thermal fuse (FU1); prevents abnormal temperature rise in the fuser (contact type)
Figure 1-8   Fuser control circuit
Fuser heater safety
circuit
TH1
FU1
H1
DC controller
Fuser heater control
circuit
Engine controllerFUSER TEMPERATURE signal 
FUSER HEATER CONTROL signal Pressure roller
Fuser film
Fuser control
Table 1-6  DC controller controlled components (continued)
12 Chapter 1   Theory of operation ENWW