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...

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...

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,...

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...

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...

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...

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...