Laser Jet 4L4ML Control Panel Overview

The HP LaserJet 4L 4ML printer's front control panel consists of 4 status lights and a front panel button situated on top of the printer. The LED lights provide a quick way to check the printer's status. Ready (Green) STEADY The printer is ready to print a job from the paper cassette. BLINKING If this light is blinking and the Data light is on steadily, the printer is receiving or processing data. STEADY If the Data light is on steadily and the Ready light is blinking, the printer is receiving...

Print Engine Control

Based on information received from the Formatter, the DC Controller sends a signal to the Laser Scanner PCA to modulate the laser diode ON and OFF. The modulated laser beam strikes the surface of a rotating scanning mirror, is directed through a focusing lens onto the Beam-to-Drum Mirror, and is then reflected onto the photosensitive drum. Synchronization of the process is achieved by continuous monitoring of the beam detect signal, which is fed back to the system from one end of the focusing...

High Voltage Power Supply Check

The High-Voltage Power Supply circuitry, on the DC Controller PCA, provides the necessary voltages for the printer's electrophotographic processes. A method for verifying the high-voltage system is given in the table below. Table 7-34 High-Voltage System Checks Table 7-34 High-Voltage System Checks 1. Toner cartridge connection points. Visually inspect the three connection points on the underside, right end of the toner cartridge. If they are dirty or corroded, clean the connections. Clean...

Numerical Parts Index

DC Controller PCA, 100-120V, LJ 4L 4ML (Exchange) DC Controller PCA, 220-240V, LJ 4L 4ML (Exchange) Laser Scanner Assembly, LJ 4L 4ML (Exchange) DC Controller PCA, 100-120V, LJ 4P 4MP (Exchanae) DC Controller PCA, 220-240V, LJ 4P 4MP (Exchange) Laser Scanner Assembly, LJ 4P 4MP (Exchange) RFI Shield, Control Panel PCA, LJ 4P 4MP Laser Scanner Assembly, LJ 4L 4ML (New) Beam-to-Drum Mirror Assembly, LJ 4L 4ML Gear Train Plate Assembly, LJ 4L 4ML DC Controller PCA, 100-120V, LJ 4L 4ML (New) DC...

Life Expectancy of Consumables

Always inspect the components listed in Table 4-1 for wear when servicing the printer. Replace these components as needed, based on printer failures or wear, not strictly on usage. Table 4-1 Life Expectancy of Consumables Table 4-1 Life Expectancy of Consumables When print becomes faint, shake cartridge to distribute remaining toner. May affect print quality and or paper movement. Look for glazing and or cracks, gear wear, sticky solenoids, etc. Fusing Assembly 100-120 V, 50 60 Hz (exchange...

Saving Toner with Econo Mode

Toner cartridge life can be extended dramatically by using the EconoMode printing feature of the printer. EconoMode can be turned on or off via the printer's front panel (LaserJet 4P 4MP only), through HP Explorer's Remote Control Panel or through a software application with the appropriate printer driver. See Chapter 3 for information on the HP Explorer Remote Control Panel. Notes EconoMode functions in portrait orientation only. Some software applications may refer to this as draft mode....

Recycling Toner Cartridges

In order to reduce the amount of plastics and other wastes entering our landfills, Hewlett-Packard has established a program for recycling used toner cartridges. Parts that do not wear are re-used in manufacture of new cartridges. Plastic and other materials are recycled. HP pays the shipping costs. In addition, a one dollar donation is shared by the Nature Conservancy and the National Wildlife Federation for each cartridge returned under this program. To join this recycling effort, follow the...

Accessories and Supplies

Laserjet Cleaning Instructions

The following items are available through your local authorized HP dealer. To find a dealer near you (or if your dealer is temporarily out of stock), call the HP Customer Information Center (800) 752-0900. 01 g Refer to Ordering Related Documentation in __Chapter 1 for documentation part numbers. 01 g Refer to Ordering Related Documentation in __Chapter 1 for documentation part numbers. 1 Mb memory upgrade, LaserJet 4L only (New) 1 Mb memory upgrade, LaserJet 4L only (Exchange) 1 Mb Memory...

Image Formation Troubleshooting

Laserjet 2420 Dirty Printing Pic

This section illustrates some image defects and their possible causes. Since there are many variables in the printing process, it is possible to encounter image defects that are not illustrated below. If you find a defect that is not illustrated, record the probable cause along with the printing environmental conditions and save a copy of the defect for future reference. VERTICAL WHITE STRIPES (See Table 7-21) VERTICAL WHITE STRIPES (See Table 7-21) VERTICAL BLACK LINES (See Table 7-22)...

Install Printer Drivers and Utilities optional

Printer drivers are specialized programs designed to allow specific software applications to function with the HP LaserJet printers. Printer utilities include such things as the HP Explorer program modules, which enhance the usability of the printer and provide convenient access to printer features outside of specific software applications. First, check the software's printer selection feature to see if the printer is listed among the available printers. If it is not, run the software's SETUP...

Alphabetical Parts Index

Beam-to-Drum Mirror Assembly, LJ 4L 4ML Beam-to-Drum Mirror Assembly, LJ 4P 4MP DC Controller PCA, 100-120V, LJ 4L 4ML (Exchanqe) DC Controller PCA, 100-120V, LJ 4L 4ML (New) DC Controller PCA, 100-120V, LJ 4P 4MP (Exchanqe) DC Controller PCA, 100-120V, LJ 4P 4MP (New) DC Controller PCA, 220-240V, LJ 4L 4ML (Exchange) DC Controller PCA, 220-240V, LJ 4L 4ML (New) DC Controller PCA, 220-240V, LJ 4P 4MP (Exchange) DC Controller PCA, 220-240V, LJ 4P 4MP (New) Gear Train Plate Assembly, LJ 4L 4ML...

Power System on DC Controller PCA

Parts Lhp 219 With Parts Name

The ac, dc and high voltage power supply circuits are all contained within the DC Controller PCA. The ac power circuitry, located on the DC Controller PCA, supplies ac voltage to the DC Power Supply whenever the printer's power cord is connected to the ac power source. The power switch must be turned ON in the LaserJet 4P 4MP. A toner cartridge must be installed and the top door closed before voltage is supplied to the High Voltage Power Supply or Main Motor drive circuitry. The DC Power Supply...

Service Errors

Service Errors inhibit further operation of the printer until some action is taken. All lights will turn on in a steady state. Pressing and holding the front panel button will reveal a pattern on the lights. The error pattern will only be displayed as long as the front panel button is held down. Use this pattern and the corresponding reference in Tables 7-6 through 7-15 to identify what type of service error has occurred. Service messages are displayed on the front Control Panel in the same...

External Assembly Locations Laser Jet 4L4ML

Front Panel Button Status LEDs Top Paper Output Tray Face-Down Manual Feed Slot Paper Release Lever Fuser Area Memory Door Figure 1-2 External Assembly Locations, LaserJet 4L 4ML Power Door Rear Access Door Face-Up Delivery Slot Paper Path Knob I O Door Paper Release Lever Fuser Area Memory Door Figure 1-2 External Assembly Locations, LaserJet 4L 4ML

External Assembly Locations Laser Jet 4P4MP

Top Door Release Button Power Switch Mechanical Paper-low Indicator 16 Character Display Manual Feed Slot Paper Cassette AC Power Input Rear Access Door Face-Up Delivery Slot SIMM Access Panel Paper Path Knob I O Panel - Paper Release Lever -Output Rollers -Fuser Area -Face-Down Output Defectors - Paper Release Lever -Output Rollers -Fuser Area -Face-Down Output Defectors Figure 1 -3 Externa Assembly Locations, LaserJet 4P 4MP