HP P 1100 Service Manual
Here you can view all the pages of manual HP P 1100 Service Manual. The HP manuals for Printer are available online for free. You can easily download all the documents as PDF.
Page 31
Fuser failure detection The DC controller determines a fuser unit failure, releases the relay to interrupt power supply to the fuser heater, and notifies the formatter of a failure state when it encounters the following conditions: ●Start up failure ◦If the main thermistor does not detect a specified temperature during the start up process of the heater in the wait period. ◦ If the main thermistor does not detect a specified temperature during the heater temperature control in the initial rotation...
Page 32
Fuser temperature control The fuser temperature control maintains the temperature of the fuser heater at its targeted temperature. The DC controller monitors the FIXING TEMPERATURE (FSRTH) signals and sends the FIXING HEATER CONTROL (FSRD) signal according to the detected temperature. The fuser heater control circuit controls the fuser heater depending on the signal so that the heater remains at the targeted temperature. Figure 1-9 Fuser-heater control circuit FSRTH DC controller RLYD FREQSNS AC input...
Page 33
Fuser protective function The protective function detects an abnormal temperature rise of the fuser unit and interrupts power supply to the fuser heater. The following three protective components prevent an abnormal temperature rise of the fuser heater: ●DC controller ◦The DC controller interrupts power supply to the fuser heater when it detects an abnormal temperature of the fuser heater. ● Fuser heater safety circuit ◦The fuser heater safety circuit interrupts power supply to the fuser heater when the...
Page 34
Low-voltage power supply The low-voltage power supply (LVPS) converts ac input voltage to dc voltage. The LVPS has two fuses on the PCA. The LVPS 24 V output is interrupted to the fuser and the high-voltage power supply if the cartridge-door interlock switch (SW501) is in the off position (cover open). WARNING!The product power switch only interrupts dc voltage from the LVPS. The ac voltage is present in the product when the power cord is plugged into a power receptacle and the power switch is in the off...
Page 35
Overcurrent/overvoltage protection The low-voltage power supply has a protective function against overcurrent and overvoltage to prevent failures in the power supply circuit. If an overcurrent or overvoltage condition occurs, the system automatically cuts off the output voltage. If the dc power is not being supplied from the low-voltage power supply, the protective function might be running. In such case, turn off the power switch and unplug the power cord. Do not plug in the power cord or turn on the...
Page 36
High-voltage power supply The high-voltage power supply (HVPS) applies biases to the following components: ●Primary charging roller ● Developing roller ● Transfer roller Figure 1-11 High-voltage power supply Primary charging bias circuit Developing bias circuit Transfer bias circuit Engine controller To primary charging roller To developing roller Photosensitive drum Transfer roller High-voltage power supply DC controlle r Cartridge 18 Chapter 1 Theory of operation ENWW
Page 37
Laser/scanner system The laser/scanner system receives VIDEO signals from the ECU and formatter and converts the signals into latent images on the photosensitive drum. The main components of the laser/scanner are the laser unit and the scanner motor unit. The DC controller sends signals to the laser/scanner to control the functions of these components. Figure 1-12 Laser/scanner system Formatter DC controller BDI signal VIDEO signal LASER CONTROL signal SCANNER MOT OR CONTROL signal Engine controller...
Page 38
Laser failure detection The DC controller determines an optical unit failure and notifies the formatter, if the laser/scanner encounters the following conditions: ●The scanner motor does not reach a specified rotation within a specified period of the scanner motor start up. ● The rotation of the scanner motor is out of specified range for a specified period during the scanner motor drive. ● The BD interval is out of a specified value during a print operation. 20 Chapter 1 Theory of operation ENWW
Page 39
Image-formation system Electrophotographic process The electrophotographic process forms an image on the paper. Following are the major components used in the process: ●Print cartridge ● Transfer roller ● Fuser ● Laser/scanner ● High-voltage power supply The DC controller uses the laser/scanner and HVPS to form the toner image on the photosensitive drum. The image is transferred to the paper and then fused onto the paper. Figure 1-13 Electrophotographic process block diagram (1 of 2) High-voltage power...
Page 40
Figure 1-14 Electrophotographic process block diagram (2 of 2) DC controlle r Engine controller Cartridge Transfer roller Developing roller Main motor Photosensitive drum Primary charging roller 22 Chapter 1 Theory of operation ENWW