Printers Chapter 28.

Printers Chapter 28

Overview In this chapter, you will learn how to
Describe current printer technologies Explain the laser printing process Install a printer on a Windows PC Recognize and fix basic printer problems Instructor Tip When gaining attention and establishing common ground, ask questions of the class such as, “How many here do not have a printer?” or “How many of you have had printer problems?” For a positive statement, tell the class, “In this lesson, we will learn about the various types of printers and how to install and troubleshoot them.”

Six Types of Printers Impact printers Inkjet printers
Dye-sublimation printers Thermal printers Solid ink printers Laser printers

Impact Printers Impact printers leave an image on the paper
Physically strike an inked ribbon against the surface of the paper Relatively slow and noisy Used for multipart forms Point of sale receipts Offices

Dot-Matrix Printers Dot-matrix printers
Use an array of pins known as printwires to strike an inked printer ribbon and produce images The case that holds the print wires is called the printhead Use either 9-pin (draft quality) or 24-pin (letter or near-letter quality) Dot-matrix printers transfer an image or text via pins.

Dot-Matrix Printers (continued)
Figure 1: An Epson FX-880+ dot-matrix printer (photo courtesy of Epson America, Inc.)

Dot-Matrix Printers (continued)
Figure 2: Inside a dot-matrix printer

Inkjet Printers An inkjet printer uses a printhead connected to a carriage that contains the ink. A belt and motor move the carriage back and forth so the ink can cover the whole page. A roller grabs paper from a paper tray (usually under or inside the printer) or feeder (usually on the back of the printer) and advances it through the printer.

Inkjet Printers (continued)
Figure 3: Typical inkjet printer

Simple devices that consist of the following: Printhead, support electronics, a transfer mechanism, and a paper-feed component Work by ejecting ink through tiny tubes Ink is heated by tiny resistors or electroconductive plates at the end of each tube. The resistors or plates boil the ink, which creates a tiny air bubble that ejects a droplet of ink onto the paper. Some inkjets use mechanical methods to eject ink. Most color printers are inkjet and produce a high-quality image.

Figure 4: Inside an inkjet printer

Figure 5: Detail of the inkjet printhead

Older inkjets had two ink cartridges Black Color Newer ones have four Cyan Magenta Yellow Or more . . . Still outrageously expensive Cost of replacements more than cost of printer! Cost of ink is between $ $8000 per gallon!

Figure 6: Inkjet ink cartridges

Inkjet Key Features Print resolution Print speed
Density of the ink Dots per inch (dpi) Print speed Pages per minute (ppm) Can print to almost anything Modern inks of archival quality (200+ years)

Dye-Sublimation Printers
Dye-sublimation printers (or thermal dye transfer printers) use sublimation. Sublimation causes something to change from a solid form into a vapor. Desublimation changes the vapor back to a solid. Used for fine detail and rich color Requires one pass for each color Produces high-quality output

Dye-Sublimation Printers (continued)
Uses CMYK method of printing Cyan, magenta, yellow, black Roll of heat-sensitive plastic film embedded with dye Fine printhead that vaporizes the dyes onto special paper Requires four passes to complete Creates continuous tone images Other processes create dithered images where the dots fake the blended colors. Professional-caliber output

Dye-Sublimation Printers (continued)
Figure 7: The dye-sublimation printing process

Thermal Printers Thermal printers
Two types: direct thermal and thermal wax Direct thermal Same as first generation of fax machines Use a heated printhead to burn dots into the surface of special heat-sensitive paper Still used for receipts at some businesses Thermal wax transfer Like dye-sublimation printers Use film coated with colored wax that gets melted onto page No need for special paper But dithered images

Laser Printers Laser printers use a mechanism called electro-photographic imaging. Produce high-quality and high-speed output of both text and graphics More expensive to purchase than inkjet or impact printers Far less expensive over the lifespan of the printer when you factor in consumables Use lasers as a light source Tech Tip Hidden Costs Some printers use consumables at a much faster rate than others, prompting the industry to rank printers in terms of their cost per page. An inexpensive printer (laser or inkjet) costs around 4 cents per page, while an expensive printer can cost more than 20 cents per page—a huge difference if you do any volume of printing. This hidden cost is particularly pernicious in the sub-$100 inkjet printers on the market. Their low prices often entice buyers, who then discover that the cost of consumables is outrageous—these days, a single set of color and black inkjet cartridges can cost as much as the printer itself, if not more!

Laser Printers (continued)
Figure 8: Typical laser printer

Laser Printer Parts Toner cartridge Photosensitive drum Erase lamp
Holds the toner Many other parts that suffer the most wear and tear are contained in the toner cartridge. Photosensitive drum Aluminum cylinder coated with particles of photosensitive compounds Erase lamp Exposes the entire surface of the photosensitive drum to light, draining any electrical charge

Laser Printer Parts (continued)
Figure 9: Components inside a laser printer

Figure 10: Laser printer’s toner cartridge

Primary corona/charge roller Enables voltage to pass to the drum and charge the photosensitive particles on its surface Creates a uniform negative charge (~600 to ~1000 volts) Laser Acts as the writing mechanism of the printer Discharges areas on drum to negative ~100 volts Called a charge roller in newer laser printers

Toner Fine powder made up of plastic particles bonded to iron particles Charged by toner cylinder to negative ~200 to ~500 volts Attracted to the parts of the drum struck by the laser Discussion Point Toner Toner is nasty! It is a very fine powder that seems to jump onto your new dress shirt from across the room! It gets into everything. Fortunately, it is relatively easy to clean up—just a damp cloth or paper towel will collect it. However, it is nearly impossible to get out of clothing. Also, many governments consider it a hazardous waste, not to be thrown in the trash. Many companies recycle toner. Please check with your local authorities for disposal methods.

Transfer corona/transfer roller Applies a positive charge to the paper Negatively charged toner is attracted to the positively charged paper. Static eliminator removes charge. Fuser assembly Attaches the toner permanently to the paper using a pressure roller and heated roller In newer printers, a transfer roller draws the toner onto the paper.

Primary power supply Provides power to the motors that move the paper, system electronics, and transfer corona High-voltage power supply Provides power to the primary corona When inserting a new toner cartridge, always turn the laser printer off before opening it. Turning gears Discrete units called gear packs or gearboxes Safety Alert Because of the high voltage present in a laser printer, you should unplug it even before changing toner cartridges.

System board Contains the main processor, ROM, and RAM ROM can often be flashed. Insufficient RAM can result in memory overflow error. Ozone filter Ozone (O3) generated by coronas can damage printer components. Filter needs to be replaced periodically. Sensors and switches Detect paper jams, empty paper trays, low toner levels, and so on

Solid Ink Printers Use solid sticks of non-toxic “ink”
Produces vibrant color Ink is melted and absorbed into the paper fibers. Only needs a single pass More expensive than other printers But ink sticks are significantly less expensive than inkjet cartridges. Solid ink offers significant advantages over color laser in the proper applications: Serious heavy monthly duty cycle: 185,000 pages average Up to 30 ppm in color Laser printers use 30X more waste over 100,000 prints 1/3 the moving parts of a laser printer One downside is the life expectancy of the printouts: Two years in office lighting Two months in sunlight

Printer Languages American Standard Code for Information Interchange (ASCII) Basic alphanumeric characters and a variety of control codes for transferring data and controlling printers Limited in its capability The PostScript page description language (PDL) developed by Adobe Device-independent printer language capable of high-resolutions and scalable fonts Printers print faster because most of the image processing is done by the printer and not the PC; PostScript defines page as single raster image. PostScript files are very portable. PDL makes PDF files

Printer Languages (continued)
Hewlett Packard developed the Printer Command Language (PCL). Expanded set of printer commands Dependent on the printer hardware Does not support advanced graphical functions Does not define the page as a single raster image

Printer Languages (continued)
Windows XP uses the Windows graphical device interface (GDI). The operating system handles print functions. If the printer has a capable raster image processor and enough RAM, you don’t need to worry about the printer language. Windows Vista/7 uses the XML Paper Specification (XPS) print path. XPS provides improved color management and print layout fidelity. Vista/7 also still support GDI.

Printer Connectivity Most local printers connect to one of two ports on the PC. DB-25 parallel port USB port Ethernet and Wi-Fi are becoming more common. The parallel port was a lot faster than the existing serial ports at the time. But it is slow by today’s standards, with a maximum data transfer rate of 150 KBps. Standard parallel ports lack bidirectional capabilities.

IEEE 1284 Standard The IEEE 1284 standard defines a high- speed bidirectional parallel port with backward compatibility. The IEEE 1284 standard requires Support for five modes of operation Compatibility mode, nibble mode, byte mode, EPP, ECP Standard methods of negotiation for determining which modes are supported A standard physical interface A standard electrical interface All data transfers are half-duplex with the IEEE 1284 standard. Many techs confuse the concept of “duplex” printing—a process that requires special printers capable of printing on both sides of a sheet of paper— with bidirectional printing. They have nothing to do with each other! Although the phrase “Centronics standard” was commonly used in the heyday of parallel ports, there actually was no such animal. Prior to the development of IEEE 1284, there was only a very loose set of “standards” adopted by manufacturers in an attempt to at least reduce incompatibility issues.

Setting Up Parallel Ports
Use the System Setup utility to configure parallel ports built into motherboards. Three options SPP (150 KBps transfers) ECP (~ 2 MBps transfers) EPP (~2.5 MBps transfers) Choose the option that best fits your device (e.g., ECP for the last generation of parallel laser printers).

Parallel Connections, Cabling, and Electricity
A standard printer cable A male DB-25 connector on one end and a 36-pin Centronics connector on the other Acceptable for transferring data at 150 KBps at distances of less than 6 feet IEEE 1284-compliant cable Can be up to 32 feet (10 m) Required for bidirectional printing Tech Tip No Cheap Cables! Some parallel cables are cheaper than the IEEE 1284 cables, but these may— or may not—work. Don’t set yourself up for unnecessary hassles— just get an IEEE 1284 cable! Installing a parallel cable is a snap. Just insert the DB-25 pin connector into the parallel port on the back of the PC and insert the Centronics connector into the printer’s Centronics port, and you’re ready to go to press!

Parallel Connections, Cabling, and Electricity (continued)
Figure 11: Standard parallel cable with 36-pin Centronics connector on one end and DB-25 connector on the other

USB Printers Most new printers use USB connections.
Most use USB type A on one end and USB type B on the other end. In almost all cases, you must install the drivers before you plug a USB printer into your computer. Some printers come with both USB and parallel connections, but this is becoming increasingly rare, so if you need a parallel printer for a system, be sure to confirm that the particular model you want will work!

Network and Other Printers
Printers can be connected on a network. Needs NIC and connection (typically RJ-45) Needs IP address (either manually assigned or automatically assigned from DHCP) Can be connected to print server Some also have wireless, IR, and Bluetooth capabilities. Other printers Rare, but may see serial or SCSI printers

The Electronic Printing Process
Click [Print]. CPU sends print job to print spooler. Spooler can handle multiple print jobs in the print queue. Spooler is a service. Killing the spooler service deletes all print jobs. Print device takes it from there.

The Electronic Printing Process (continued)
Raster image Impact printers print a line at a time. Laser printers generate a raster image of the page. A raster image is a pattern of dots. The raster image processor (RIP) chip translates the raster image into commands for the laser printer.

RIP needs RAM in order to store this data. Mem Overflow error indicates insufficient RAM. Add RAM, reduce the resolution, or print smaller graphics. HP LaserJet 21 error means the data is too complex. Reduce complexity by using fewer fonts and less formatting, reducing graphics resolution, and so on. Resolution enhancement technology (RET) Enables the printer to insert smaller dots among the characters to smooth out jagged curves. Disabling RET helps reduce MEM OVERFLOW errors.

Resolution A laser printer can print at different resolutions. Resolution is expressed in dots per inch (dpi)— for example, 600 × 600 or 1200 × 1200 dpi. The first number is the horizontal resolution—how fine a focus can be achieved by the laser. The second number is the vertical resolution—the smallest increment by which the drum can be turned.

Figure 12: RET fills in gaps with smaller dots to smooth out jagged characters.

Physical Side of the Process
6 Steps of the physical laser printing process Charging Exposing Developing Transferring Fusing Cleaning

Charge the Drum The drum is charged by applying a negative charge to the entire surface. Charged by primary corona wire Between ~600 and ~1000 volts

Charge the Drum (continued)
Figure 13: Charging the drum with a uniform negative charge

Exposing and Developing the Image
A laser is used to write and develop an image on the surface of the drum. Every particle hit by the laser releases most of its negative charge into the drum. Toner is attracted to the more positively charged areas of the drum; this is the develop portion of the process.

Exposing and Developing the Image (continued)
Figure 14: Writing the image and applying the toner

Transfer the Image Using the transfer corona, the paper is charged positively. The negatively charged toner particles leap from the drum to the paper. Discussion Point Charges Remember the phrase from high-school science class, “opposites attract”? That is the underlying principle behind laser printers. The toner jumps around from one place to another based on the positive or negative charges it is following. The negatively charged toner seeks out and jumps to the positively charged paper.

Fuse the Image Image fused to the paper
The heat roller, made of a nonstick material, and the pressure roller are used to fuse the image onto the paper. Toner particles melted into the page. Static charge eliminator removes the charge from the paper. This prevents the paper from sticking to the drum. The heated roller produces enough heat to melt some types of plastic media, particularly overhead transparency materials. This could damage your laser printer (and void your warranty), so make sure you’re printing on transparencies designed for laser printers!

Fuse the Image (continued)
Figure 15: Transferring the image to the paper and fusing the final image

Clean the Drum Printing process ends by physically and electrically cleaning the photosensitive drum. Physically by scraping the surface of the drum with a rubber cleaning blade Electrically with an erase lamp to completely discharge any particles

Clean the Drum (continued)
Figure 16: Cleaning and erasing the drum

Printing in Windows The physical printer is called a print device.
The printer is a program that controls one or more print devices. One printer can support more than one print device. Print drivers Print spooler

Printing in Windows (continued)
Figure 17: Printer driver and spooler in Windows

Setting Up Printers If the printer is not detected, use the Printers applet from the Control Panel and select Add Printer (XP), or the Printer icon (Vista). Windows has an option that will automatically detect and install a plug-and-play printer. The Add Printer Wizard enables you to install a local printer or a network printer. Windows divides printer installation into two scenarios: a printer connected directly to a PC or a standalone printer connected to a switch or router. With USB printers (and infrared printers, for that matter), Windows won’t even wait for you to do anything—once you connect a printer (or point the IR beam at a compatible PC), Windows immediately detects and installs the printer.

Setting Up Printers (continued)
Figure 18: Automatically detecting plug-and-play printers in Windows XP

Installing a local printer: Since Windows will automatically detect and install USB printers (or any other plug-and-play printer), this option is most commonly used to install printers using a parallel connection or to install standalone network printers using an IP address. Should not need to use Add Printer Wizard or IP address with a standalone USB printer.

Installing a local printer (continued): Windows won’t automatically detect a new parallel device. For a parallel port printer using Windows XP, check the Automatically detect and install my Plug and Play printer option. When you check this box and click Next, Windows XP will run a search for any plug-and-play printers, including those connected via parallel cables. Windows Vista and Windows 7 don’t include this option; you’ll need to configure parallel-connected printers manually by selecting a port and driver.

Installing a local printer (continued): If you need to install a standalone network printer using its IP address, uncheck the Automatically detect and install my Plug and Play printer option in Windows XP and click Next. In Windows Vista and Windows 7, click Add a local printer. In the Create a new port drop-down box, select Standard TCP/IP Port. Click Next. Type the IP address here.

Installing a local printer (continued): Whether you use a parallel port or a TCP/IP port, you’ll need to manually select the proper driver from Windows drivers or a supplied disk (requires admin privileges). You must decide whether the new local printer should be the default printer and whether you want to share it with other PCs on the network.

Figure 19: Selecting drivers

Installing a network printer—setup is not much different than installing a standalone In Windows Vista or Windows 7, the Add Printer Wizard will scan for any available printers on your local network, and the printer will appear. If you need to, you can pick from a list of available drivers or use the disc that came with the printer. Windows XP doesn’t include this automatic discovery feature, and if Windows Vista or Windows 7 fails to find your printer, you’ll need to configure the network printer manually.

Figure 20: List of available shared printers on a network

Installing a network printer (continued) If you are on a workgroup, you can browse for a printer on your network, connect to a specific printer (using its name or URL), or use a TCP/IP address or hostname (Windows Vista/7 only). In a domain, most of those options remain the same, except that instead of browsing the workgroup, you can search and browse the domain using several search parameters, including printer features, printer location, and more.

Figure 21: Options for finding network printers

Installing a network printer (continued) If you are a member of a Windows 7 homegroup and printer sharing is enabled, all printers connected to the homegroup are shared with you automatically. The process for sharing a local printer and a network printer is identical, because Windows considers both printers to be installed on your PC and under your control.

Figure 22: Installed default printer in the Printers and Faxes applet

Optimizing Print Performance
Printout may not match screen colors. Monitors use RGB. Printers use CMYK. They don’t always match exactly. Calibration Manually calibrate monitor Print a test image and adjust monitor to match printout Automatically calibrate printer Use an International Color Consortium (ICC) color profile Instructs the printer to print colors a certain way DisplayMate ColorVision Spyder To change the profile, check the Color Management tab in Printer Properties.

Optimizing Print Performance (continued)
Add memory Best first upgrade for printers Increases speed, especially with graphics Install a network card Better printers can be freed from needing print server Only need DHCP (and DNS) Not in book

Optimizing Print Performance (continued)
Configure application to request low- resolution or draft mode. Optimizing increases print speed. Creates a lower quality image—but does so quickly Manage printer availability Can set when particular printers are available Use to restrict access to printer during critical times Right-click printer | Properties | Advanced tab

Troubleshooting Printers

General Troubleshooting Issues
Tools of the trade Multimeter Cleaning solutions such as denatured alcohol Extension magnet for retrieving loose screws CD or USB drive with test patterns Phillips-head and flat-head screwdrivers Tech Tip Readme Files You’ve seen how to get your system to recognize a printer, but what do you do when you get a brand-new printer? Like most peripherals, you’ll have an installation CD that contains various useful files. One of the most important, but least used, tools on this CD is the Readme file. This file, generally in TXT format, contains the absolute latest information on any idiosyncrasies, problems, or incompatibilities related to your printer or printer driver. Usually, you can find it in the root folder of the installation CD, although many printer drivers install the Readme file on your hard drive, so you can access it from the Start menu. The rule here is read first to avoid a headache later!

General Troubleshooting Issues (continued)
Print job never prints Is the printer on? Connected? Check all cables, ports, and power involved. Check the appropriate printer applet for your version of Windows. If you don’t see the printer you are looking for, you’ll need to reinstall it using the Add Printer Wizard. If you attempt to use a printer shared by another PC and Windows pops up with an “Access Denied” error, you might not have permission to use the printer. Go to the host PC and check the Security tab of the Printer Properties dialog box. Make sure your user account is allowed to use the printer. Can bypass spooler if desired

Print job never prints (continued) Is there paper and toner or ink? Is the print spooler overflowing, corrupt, or paused? Jobs in the print spooler can be stopped and restarted. If the printer spooler is the problem, you can bypass the spooler by selecting “Print directly to the printer”

Print job never prints (continued) If the print spooler is overwhelmed, you might need to delete print jobs. Try restarting the print spooler service. You’ll need administrator privileges to do this. In the service applet, scroll down and find the service named Print Spooler. Right-click on the service and select Stop. After it has stopped, right-click on the service again and select Start. You should be able to print using the print spooler again. You can also manually start and stop the print spooler from the command line: NET START SPOOLER NET STOP SPOOLER

Figure 23: Print spooler

Figure 24: Print spool settings

Strange sizes Points to setup error Check the Page Setup option in the application

Figure 25: Page Setup options for Microsoft Word

Misaligned or garbage prints A corrupted or incorrect driver—reinstall You may have asked the printer to do something it can’t do, such as printing PostScript with a PCL driver. Consumables Printer components should be properly disposed of to avoid environmental hazards. Some companies buy used toner cartridges. Check the material safety data sheet (MSDS).

Other Issues Sharing multiple printers on a parallel port
A mechanical switch box may be used to share multiple printers. Laser printers should only be used with electronic switch boxes. Crashes on power up Printers require a lot of power on start up. HP recommends that you turn on the laser printer first and then the PC.

Troubleshooting Impact Printers
Dot-matrix printers require regular maintenance. The printhead and the platen should be cleaned with denatured alcohol. This prevents problems such as white bars on text, dots and smudges on paper, and so on. Gears and pulleys should be lubricated according to the manufacturer’s specifications. Bad-looking text Dirty or damaged printhead—clean with denatured alcohol or replace. Bad-looking page Clean the platen with denatured alcohol. Adjust the platen. Remember to replace the ribbon occasionally.

Troubleshooting Thermal Printers
Thermal printers are simple to troubleshoot and maintain. With direct thermal printers, you need to worry about only three things: the heating element, the rollers, and the paper. With thermal wax printers, you also need to care for the wax ribbon. To clean the heating element, turn off the thermal printer and open it according to the manufacturer’s instructions. Use denatured alcohol and a lint-free cloth to wipe off the heating element. Use a little pressure to get it completely clean.

Troubleshooting Thermal Printers (continued)
Clean the rollers with a cloth or compressed air. You want to keep them free of debris so they can properly grip the paper. Replacing the paper is as easy as sliding off the old roll and replacing it with a new one. Remember to feed the paper through the heating element, because otherwise you won’t print anything.

Troubleshooting Thermal Printers (continued)
Replacing the ribbon is similar to replacing the roll of paper; make sure to feed it past the heating element, or the printer won’t work properly. Your printer’s manufacturer should include any special instructions for installing a new ribbon.

Troubleshooting Inkjet Printers
Use the maintenance software that came with the printer setup program. Align and clean the print heads. Ink will dry out in a short time if an inkjet printer is not used—the ink in the tiny nozzles of the printhead dries out. Multisheet grab Fan the paper. Let the printer rest if you’ve been printing a lot. Humidity and overheated printer can be an issue—let it cool. Clean the small tank where the printhead rests or parks with a paper towel. If color seems fuzzy, run an alignment page on the jets to see if they’ve lost alignment. Note: All inkjet inks are water-based, and water works better than alcohol to clean them up. Cleaning the heads on an inkjet printer is sometimes necessary, but I don’t recommend that you do it on a regular basis as preventive maintenance. The head-cleaning process uses up a lot of that very expensive inkjet ink—so do this only when a printing problem seems to indicate clogged or dirty print heads!

Troubleshooting Inkjet Printers (continued)
Figure 26: Inkjet printer maintenance screen

Laser Printer Maintenance
Keep printer clean. Excess toner and paper dust commonly cause the printer to get dirty. Clean with a special low-static vacuum designed for electrical components (indoors) or a can of compressed air (outdoors!). The rubber guide rollers will pick up dirt and paper dust over time, which causes paper jams. Before you service a laser printer, always, ALWAYS turn it off and unplug it! Don’t expose yourself to the very dangerous high voltages found inside these machines. The photosensitive drum, usually contained in the toner cartridge, can be wiped clean if it becomes dirty, but be very careful if you try this! If the drum becomes scratched, the scratch will appear on every page printed from that point forward. The only repair in the event of a scratch is to replace the toner cartridge. Failure of the thermal fuse (used to keep the fuser from overheating) can necessitate replacing the fuser assembly. Some machines contain more than one thermal fuse. As always, follow the manufacturer’s recommendations. Many manufacturers have kits that alert you with an alarm code to replace the fuser unit and key rollers and guides at predetermined page counts. Always let the fuser assembly cool down before cleaning it—they operate at 200 to 300 degrees Fahrenheit!

Laser Printer Maintenance (continued)
Figure 27: Low-static vacuum

Laser Printer Maintenance (continued)
Certain components should be replaced regularly. Follow manufacturer’s recommendations. Most manufacturers sell maintenance kits for most of their printers. After installing, reset the page count. Clean or replace ozone filters regularly. Check and clean fuser assembly and heat roller. Note: Failure of the thermal fuse (used to keep the fuser from overheating) can necessitate replacing the fuser assembly. Some machines contain more than one thermal fuse. As always, follow the manufacturer’s recommendations. Many manufacturers have kits that alert you with an alarm code to replace the fuser unit and key rollers and guides at predetermined page counts.

Troubleshooting Laser Printers
Print a diagnostic print page as a first- step in troubleshooting. Hold down the On Line button as the printer is started as a first step in troubleshooting. Blank paper May be out of toner. Check the imaging drum to see if image is on drum but not transferred to paper. Could be transfer corona or high-voltage power supply. Dirty or smudged printouts Light dusting of toner on the paper (front or back) indicates dirty printer. Clean the printer. If the printout looks smudged, the fuser isn’t properly fusing the toner to the paper. Depending on the paper used, the fuser needs to reach a certain temperature to fuse the toner. If the toner won’t fuse to the paper, try using a lighter-weight paper. You might also need to replace the fuser.

Troubleshooting Laser Printers (continued)
Ghosting Can be light ghosting or dark ghosting Light ghosting explored on next slide Dark ghosting can be from a damaged drum— replace the toner cartridge. Low temperature or low humidity can aggravate ghosting problems.

Light ghosting Caused by printing an extremely dark or complex image Referred to as developer starvation Lower the resolution. Use different pattern. Avoid 50 percent grayscale and dot-on/dot-off patterns. Change the layout so grayscale patterns do not follow black areas. Make dark patterns lighter and light patterns darker. Print in landscape. Adjust print density and RET settings. Print a completely blank page before the next one.

Vertical white lines Clogged toner Try shaking the toner cartridge or replacing it. Blotchy print Uneven dispersion of toner Try shaking the toner cartridge from side to side. Make sure the printer is level. Make sure the paper is not wet in spots. Check the fusing rollers and photosensitive drum for foreign objects.

Spotty print Try wiping off the fuser rollers. Check the drum for damage. Embossed effect Like putting a penny under a piece of paper and rubbing it with a lead pencil. A foreign object on a roller A foreign object on the photosensitive drum Replace the toner cartridge.

Incomplete characters These may occur on transparencies. Try adjusting the print density. Creased pages Cotton bond paper is more susceptible. Try using a different paper type.

Paper jams Do not pull on the paper to remove it. You can damage the printer by pulling out jammed paper. Check manufacturer’s jam-removal procedure. If there is no jammed paper, sensors may be bad. Pulling multiple sheets Try using a different ream of paper—if that works, the issue is humidity. Check the separation pad—a small piece of rubber or cork that separates the sheets as they are pulled from the paper tray.

Warped, overprinted, or poorly formed characters Paper that is too rough or too smooth Don’t open a ream of paper until you’re ready to load it into the printer. Always fan the paper before loading it in the printer. Do a printer self-test to determine whether the problem is the printer or the computer. Replace the toner cartridge, check the cabling, replace the data cable. Turn off advanced functions and high-speed settings; perhaps they are not supported by your software configuration.

Beyond A+ Multifunction peripherals— manufacturers started combining various peripherals to create multifunction peripherals, or MFPs. These devices can include printers, scanners, fax machines, photocopiers, and more. All of the standard connection options are available, including USB, parallel, Ethernet, Wi-Fi, and more.

All functions are available using a single connection.
Beyond A+ (continued) All functions are available using a single connection. Many multifunction devices also include functions that don’t require a PC at all, such as photocopying and faxing. You can even print files from a digital camera’s memory card without plugging the MFP into a PC.

Beyond A+ (continued) Figure 28: All-in-one printer/scanner/fax machine/copier/coffee maker/iPod dock

Printers Chapter 28.

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