Printers Chapter 20

Overview In this chapter, you will learn 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 oo 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!”

Getting the Right Sound Card Essentials CompTIA A+ Essentials Getting the Right Sound Card Printer Technologies

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)

Inkjet Printers Inkjet printers 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 ink-jet and produce a high-quality image

Inside an Inkjet Printer

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

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 and then back into a solid Used for fine detail and rich color One pass for each color Produces high-quality output

Thermal Printers Thermal printers Same as first generation of fax machines Two types: direct thermal and thermal wax Use a heated printhead to burn dots into the surface of special heat-sensitive paper Still used for receipts at some businesses

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 than inkjet or impact printers 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 Printer Parts Toner cartridge Photosensitive drum Erase lamp Holds the toner Many other parts that suffer the most wear and tear contained in toner cartridge Photosensitive drum Aluminum cylinder coated with particles of photosensitive compounds Erase lamp Exposes the entire surface of the photosensitive drum to light

Laser Printer Parts Primary corona Laser Toner Enables voltage to pass to the drum and charge the photosensitive particles on its surface Laser Acts as the writing mechanism of the printer Toner Fine powder made up of plastic particles bonded to iron particles 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.

Laser Printer Parts Transfer corona Fuser Fuser assembly Applies a positive charge to the paper Fuser Attaches the toner permanently to the paper using the pressure roller and heated roller Fuser assembly Fuses the toner to the paper

Laser Printer Components

Laser Printer Parts Primary power supply High-voltage 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.

Laser Printer Parts System board Ozone filter Sensors and Switches Contains the main processor, ROM, and RAM ROM can often be “flashed” Not enough RAM results in memory overflow error Ozone filter Ozone (O3) can damage printer components Filter needs to be replaced periodically Sensors and Switches Detects paper jams, empty paper trays, low toner levels, and so on

Solid Ink Printers Use solid sticks of nontoxic “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

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 files are very portable

Printer Languages Hewlett Packard developed the Printer control 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 Windows 2000/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

Printer Connectivity Most printers connect to one of two ports on the PC DB-25 parallel port USB port The parallel port was a lot faster than the existing serial ports at the time Slow by today’s standards with a maximum data transfer rate of 150 KBps IEEE (Institute of Electrical and Electronics Engineers) 1284 standard addressed standardizing parallel ports

IEEE 1284 Standard 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.

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 six feet IEEE 1284-compliant cable Can be up to 32 feet 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!

USB and FireWire Printers Most new printers now use USB connections Most use USB type A on one end and USB type B on the other end FireWire Works as easily as USB USB B 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! USB A

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 and Bluetooth capabilities Other printers Rare, but may see serial or SCSI printers

The Laser Printing Process IT Technician CompTIA A+ Technician The Laser Printing Process

Physical Side of the Process California Cows Won’t Dance The Fandango Clean Charge Write Develop Transfer Fuse Discussion Point Mnemonic The A+ exam expects students to know the steps of the laser printing process in order. To help students remember the laser printing process order—Clean, Charge, Write, Develop, Transfer, Fuse—try this mnemonic: California Cows Won’t Dance The Fandango. It may sound silly, but it works!

Clean the Drum Printing process begins 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

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

Write and Develop the Image A laser is used to write and develop an image on the surface of the drum Every particle hit by the laser will release most of its negative charge into the drum 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.

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 charge from paper Stops paper from sticking to 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!

The Electronic Printing Process Raster image Laser printers generate a raster image of the page A raster image is a pattern of dots Raster image processor (RIP) chip translates the raster image into commands for the laser

The Electronic Printing Process 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 MEM OVERFLOW errors

The Electronic Printing Process Resolution A laser printer can print at different resolutions Resolution is expressed in dots per inch (dpi) such as 600 x 600 or 1200 x 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

Installing a Printer in Windows

Printing in Windows 2000/XP 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 Exercise Troubleshooting As usual, surreptitiously make changes without the students present. This will more closely emulate a real tech-environment service call. Have some bad cables available for students to eliminate as the cause of a printer problem. Delete printer drivers. Move different printers from one computer to another (without reinstalling the drivers) so the computer doesn’t recognize the printer. Use old toner cartridges or ink cartridges. While a laser printer is running a sheet of paper through, kill the power to simulate a paper jam. Then have the students perform the service calls.

Setting Up Printers PnP devices usually works after plugging them in If necessary, can use applets to install Open the Printers applet Windows XP: Start  Printers and Faxes Windows 2000: Start  Settings  Printers Or find applet in Control Panel Click the Add Printer icon to start the Add Printer Wizard

Setting Up Printers Add Printer wizard Select local or network printer Select a printer port

Setting Up Printers Add Printer Wizard Add the driver Windows Update easiest to use (if driver installed) Or can download driver from manufacturer or use CD accompanying printer and use Have Disk Checkmark indicates default printer

Optimizing Print Performance Printout may not match screen colors Monitors use RGB Printers use CMYK Both 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

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 or flat-head screwdriver 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 Job never prints Is the printer on? Connected? Does it have paper? Check the spooler status Can bypass spooler if desired Strange sizes Points to setup error Check the Page Setup option in the application

General Troubleshooting Issues 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

Other Issues Sharing multiple printers Crashes on power up 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 Dot Matrix Printers Dot-matrix printers require regular maintenance The printhead and the platen should be cleaned with denatured alcohol 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 Replace the 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 can be an issue Clean the small tank where the printhead rests or parks with a paper towel All inkjet inks are waterbased, and water works better than alcohol to clean them up.

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 Out of toner Print a diagnostic page, remove the toner cartridge, and look at the imaging drum—if an image is there, the transfer corona or high-voltage power supply is bad

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 or a can of compressed air 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 because they operate at 200 to 300 degrees Fahrenheit!

Laser Printer Maintenance Certain components should be replaced regularly Follow manufacturers recommendations Most manufacturers sell maintenance kits for most of their printers Clean or replace ozone filters regularly Check and clean fuser assembly and heat roller

Troubleshooting Laser Printers Blank Paper May be out of toner Check the imaging drum to see if image is on drum but just not transferred to paper Could be transfer corona or high-voltage supply Dirty printouts Light dusting of toner on the paper (front or back) indicates dirty printer Clean the printer

Troubleshooting Laser Printers 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

Troubleshooting Laser Printers Light ghosting Caused by printing an extremely dark or complex image Referred to as developer starvation Lower the resolution Use different pattern Avoid 50% 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

Troubleshooting Laser Printers 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

Troubleshooting Laser Printers 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

Troubleshooting Laser Printers 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

Troubleshooting Laser Printers Paper jams Do not pull on the paper to remove it Can damage the printer by pulling jammed paper out 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

Troubleshooting Laser Printers Warped, overprinted, or poorly formed characters Paper that is too rough or too smooth Don’t open a ream of paper until it is loaded into the printer Always fan the paper before loading it in the printer Do a printer self-test to determine if it 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 to see if they may not be supported by your software configuration

Also called IEEE 1284.4 standard Beyond A+—DOT4 Also called IEEE 1284.4 standard Created for multifunction peripherals (MFP) Devices that combine printer, fax, and scanner in one piece of equipment Allows simultaneous sending and receiving across a single physical channel