CompTIA A+ Complete Study Guide phần 3 pptx

Performing Preventative Maintenance on Personal Computers 129 air from time to time can prevent damage to the components. While you’re cleaning the com- ponents, be sure to clean any cooling fans in the power supply or on the heat sink. To clean the power supply fan, blow the air from the inside of the case. When you do this, the fan will blow the contaminants out the cooling vents. If you spray from the vents toward the inside of the box, you’ll be blowing the dust and grime inside the case or back into the fan motor. One way to ensure that the environment has the least possible effect on your computer is to always leave the blanks in the empty slots on the back of your box. These pieces of metal are designed to keep dirt, dust, and other foreign matter from the inside of the computer. They also maintain proper airflow within the case to ensure that the computer doesn’t overheat. Performing Preventative Maintenance on Personal Computers This section outlines some preventative maintenance products and procedures. Preventative main- tenance is one of the most overlooked ways to reduce the cost of ownership in any environment. Cleaning a computer system is the most important part of maintaining it. Computer com- ponents get dirty. Dirt reduces their operating efficiency and, ultimately, their life. Cleaning them is definitely important. But cleaning them with the right cleaning compounds is equally important. Using the wrong compounds can leave residue behind that is more harmful than the dirt you’re trying to remove! Most computer cases and monitor cases can be cleaned using mild soap and water on a clean, lint-free cloth. Make sure the power is off before you put anything wet near a computer. Dampen (don’t soak) a cloth with a mild soap solution, and wipe the dirt and dust from the case. Then wipe the moisture from the case with a dry, lint-free cloth. Anything with a plastic or metal case can be cleaned in this manner. Don't drip liquid into any vent holes on equipment. CRTs in particular have vent holes in the top. To clean a monitor screen, use glass cleaner designed specifically for monitors and a soft cloth. Don’t use commercial window cleaner, because the chemicals in it can ruin the antiglare coating on some monitors. To clean a keyboard, use canned air to blow debris out from under keys, and use towelettes designed for use with computers to keep the key tops clean. If you spill anything on a keyboard, you can clean it by soaking it in distilled, demineralized water. The minerals and impurities have been removed from this type of water, so it won’t leave any traces of residue that might interfere with the proper operation of the keyboard after cleaning. Make sure you let the keyboard dry for at least 48 hours before using it. 4831x.book Page 129 Tuesday, September 12, 2006 11:59 AM 130 Chapter 2  Effectively Working with Personal Computer Components The electronic connectors of computer equipment, on the other hand, should never touch water. Instead, use a swab moistened in distilled, denatured isopropyl alcohol (also known as electronics cleaner and found in electronics stores) to clean contacts. Doing so will take the oxidation off the copper contacts. A good way to remove dust and dirt from the inside of the computer is to use compressed air. Blow the dust from inside the computer using a stream of compressed air. However, be sure you do this outdoors, so you don’t blow dust all over your work area or yourself. You can also use a vacuum, but it must be designed specifically for electronics—such models don’t generate ESD and have a finer filter than normal. To prevent a computer from becoming dirty in the first place, control its environment. Make sure there is adequate ventilation in the work area and that the dust level isn’t excessive. To avoid ESD, you should maintain 50 to 80 percent humidity in the room where the com- puter is operating. You should visually inspect the computer for signs of distress within it. Discolored areas on the board are often caused by overheating. The overheating can be caused by power surges or overclocking and is an indication that all is not right. One unique challenge when cleaning printers is spilled toner. It sticks to everything and should not be inhaled. Use a vacuum designed specifically for electronics. A normal vacuum’s filter isn’t fine enough to catch all the particles, so the toner may be circulated into the air. If you get toner on your clothes, use a magnet to get it out (toner is half iron). Removable media devices such as floppy and CD drives don’t usually need to be cleaned during preventative maintenance. Clean one only if you’re experiencing problems with it. Cleaning kits sold in computer stores provide the needed supplies. Usually, cleaning a floppy drive involves using a dummy floppy disk made of semi-abrasive material. When you insert the disk in the drive, the drive spins it, and the abrasive action on the read-write head removes any debris. An uninterruptible power supply (UPS) should be checked periodically as part of the pre- ventative maintenance routine to make sure that its battery is operational. Most UPSs have a Test button you can press to simulate a power outage. You will find that batteries wear out over time, and you should replace the battery in the UPS every couple of years in order to keep the UPS dependable. The motherboard contains a battery, as well, which is used to maintain internal settings when power is not provided to the unit. Resembling large watch batteries, these entities tend to have a considerable life, on average, but can lose their charge over time. If you boot a system and find that the date and time and other variables have not been maintained, you will want to change the internal battery. Remember, preventative maintenance is more than just manipulating hardware; it also encompasses running software utilities on a regular basis to keep the file system fit. These utilities can include Disk Defragmenter, ScanDisk, Check Disk, and Disk Cleanup. 4831x.book Page 130 Tuesday, September 12, 2006 11:59 AM Summary 131 Summary In this chapter, you finished learning about personal computer components, specifically storage devices, display devices, and input and multimedia devices. In addition, we discussed identifying various problems that can occur, as well as various solutions or approaches to finding a solution. Finally, we walked through troubleshooting the- ory and techniques and concluded by examining some preventative maintenance recommen- dations and issues. Exam Essentials Know how many pins an IDE/PATA/ATA-5/ATA-6 cable has. A cable for use with these technologies has 40 pins. You’re likely to be asked to choose a cable in a scenario question simply by knowing how many pins the drive requires. Know how a controller works in a master/slave environment. When you have a master and a slave, only one of the two controllers controls data transfers. You’re likely to be asked a scenario question that relates to this environment. Know what other devices besides hard drives use IDE interfaces. With the popularity of IDE technology, manufacturers have introduced tape drives and CD-ROMs that use IDE interfaces. Know what can be used to clean computer components. Many types of cleaning solutions can be used to perform these procedures. Be familiar with which option is best for each com- ponent. Which ones can be cleaned with water? Which ones require alcohol? Which ones need canned air? Know why the proper cleaning solutions should be used. Using the wrong cleaning solution can damage components. Along with choosing the right cleaning solution, understand why the improper solutions are inappropriate for a particular component. 4831x.book Page 131 Tuesday, September 12, 2006 11:59 AM 132 Chapter 2  Effectively Working with Personal Computer Components Review Questions 1. Which of the following steps is not necessary when replacing a floppy drive? A. Turn off the PC. B. Disconnect the power supply from the drive. C. Disconnect the ribbon cable from the drive. D. Disconnect the audio cable from the drive. 2. When attaching a ribbon cable to a drive, if there is no marking for pin 1, which way should you orient the red stripe? A. Closest to the power supply connector B. Farthest away from the power supply connector C. Facing the top of the drive D. Facing the bottom of the drive 3. To fix a bad power supply in a desktop PC, you should ____________. A. Remove and replace the entire power supply box. B. Disassemble the power supply and replace the coils. C. Disassemble the power supply and replace the capacitors. D. Disassemble the power supply and replace the resistors. 4. How many bits of data does a high-speed serial cable carry simultaneously in a single direction? A. 1 B. 8 C. 32 D. Depends on the cable 5. Which of the following could not be connected to an IDE interface on a typical motherboard? A. ATA-2 B. EIDE C. ATAPI D. All of these could be connected. 6. What do UltraDMA/66 and higher require? A. Cable Select configuration B. An 80-wire cable C. Operating system support D. All of the above 4831x.book Page 132 Tuesday, September 12, 2006 11:59 AM Review Questions 133 7. On the primary IDE channel, if a single hard disk is attached, its jumper should be set to ________. A. Slave B. Single if available; otherwise Master C. Master D. Boot 8. Which type of SCSI termination uses voltage regulators inside the terminator? A. Active B. Passive C. High-byte D. All of the above 9. You install a new UltraATA/100 hard disk in an old PC, connecting it directly to the primary IDE on the motherboard. You use the 80-wire ribbon cable that came with it. Performance testing indicates that the new drive is not performing up to UltraATA/100 standards. What could you try next? A. Reformat the hard disk using NTFS 5.0. B. Add an ATA/100-compatible expansion board and connect the drive to it. C. Partition the disk into smaller logical drives. D. Set up the drive in BIOS Setup to use PIO mode 4. 10. Which AT command resets the modem? A. ATH0 B. ATM0 C. ATZ D. ATDT 11. While inspecting a motherboard, you notice a discolored area. What is usually a cause of this? A. Spilled liquid B. Improper manufacture C. Power surge D. Underclocking 12. What does the red stripe on a ribbon cable indicate? A. Pin 16 B. Pin 1 C. The manufacturer’s trademark D. Parity 4831x.book Page 133 Tuesday, September 12, 2006 11:59 AM 134 Chapter 2  Effectively Working with Personal Computer Components 13. Display devices can be connected to a PC using DB-15 connectors or ________. A. HDT B. DVI C. VBA D. VBP 14. What utility can be used with Windows XP to format drives? A. Disk Design B. Disk Plan C. Disk Management D. Disk Prep 15. Which ATA standard supports UltraDMA/133? A. ATA-7 B. ATA-8 C. ATA-9 D. ATA-10 16. What type of female DB-style connector does SCSI-2 use? (Choose all that apply.) A. 25-pin B. 50-pin C. 68-pin D. 72-pin 17. Internally, what type of wire ribbon cable does SCSI use? A. 25-pin B. 50-pin C. 68-pin D. 72-pin 18. When changing display devices or upgrading to a newer one, what is one of the most crucial components to have? A. Manufacturer’s resolution recommendations B. Antistatic mat C. Ribbon cable D. Correct driver 4831x.book Page 134 Tuesday, September 12, 2006 11:59 AM Review Questions 135 19. Every computer has a diagnostic program built into its BIOS called the ________. A. CMOS B. BIOS C. POST D. DNS 20. What two devices are commonly used to cool components within a PC? (Choose two.) A. Fans B. Compressed air C. Freon D. Heat sinks 4831x.book Page 135 Tuesday, September 12, 2006 11:59 AM 136 Chapter 2  Effectively Working with Personal Computer Components Answers to Review Questions 1. D. There is no audio cable associated with a floppy drive; that’s only for CD drives. All the other listed actions are necessary when replacing a floppy drive. 2. A. Closest to the power supply connector is a general rule for stripe orientation. Because the cable attaches horizontally to the drive, there is no “facing the top” or “facing the bottom” orientation. 3. A. You should never attempt to disassemble a power supply, because of the risk of electrocu- tion and the relatively low cost of a new power supply. 4. A. By definition, a serial cable carries only one bit of data at a time. 5. D. All of these are types of IDE. ATA-2 and EIDE are the same thing—a rather dated but still useful version of the ATA standard. ATAPI is a non-hard-disk type of IDE device. 6. B. UltraDMA/66 requires a special ribbon cable with extra wires to cut down on crosstalk. It does not require Cable Select to be in use, and it does not require specific operating system support because it operates at a lower level than the OS. 7. B. If there is a Single setting, it should be used. Otherwise use Master. Slave is never appropri- ate for a single drive. There is no such jumper setting as Boot. 8. A. Active termination uses voltage regulators. Passive termination uses resistors. High-byte termination is a specialty type that terminates only half of the bytes; it’s used to transition between a wide and a narrow device on the same chain. 9. B. Because it is an older PC, its IDE interface probably does not support UltraATA/100, so add- ing an expansion board would be the next step. Repartitioning or reformatting would make no difference. Using a PIO mode in BIOS could actually impede the drive’s performance. 10. C. ATZ is a reset command. ATH0 hangs up. ATM0 turns off the speaker. ATDT dials whatever number follows it. 11. C. Discolored areas on the board are often caused by overheating. This can be the result of power surges or overclocking. 12. B. The red stripe on the cable indicates pin 1. 13. B. Digital Visual Interface (DVI) connectors can be used to connect display devices to PCs. 14. C. The Disk Management utility can be used in Windows XP to format drives. 15. A. ATA-7 supports UltraDMA/133. 16. A, B, C. SCSI-2 uses a 25-, 50-, or 68-pin female DB-style connector. 17. B. SCSI internal cabling uses a 50-wire ribbon cable with several keyed connectors. 4831x.book Page 136 Tuesday, September 12, 2006 11:59 AM Answers to Review Questions 137 18. D. The correct driver is needed in order to assure the new display device works as it should. 19. B. Every computer has a diagnostic program built into its BIOS called the power-on self-test (POST). 20. A, D. Heat sinks and fans are commonly used to cool components within a PC. 4831x.book Page 137 Tuesday, September 12, 2006 11:59 AM 4831x.book Page 138 Tuesday, September 12, 2006 11:59 AM [...]... 7680 × 4800 pixels (37 million total) at a16:10 aspect ratio 4 831 xc 03. fm Page 152 Thursday, September 14, 2006 3: 11 PM 152 Chapter 3 Understanding Laptops and Portable Devices Table 3. 1 highlights the some LCD video standards, their standard resolutions, and their aspect ratio: TABLE 3. 1 LCD Video Standards Name Resolution Ratio Extended Graphics Array (XGA) 800 × 600 1024 × 768 4 :3 4 :3 Super eXtended... with a special cable to a proprietary connector Figure 3. 4 shows an example of one of these connectors, and Figure 3. 5 shows an example of a laptop floppy drive Notice how thin the floppy drive is and how compact the electronics are FIGURE 3. 4 A proprietary floppy connector 4 831 xc 03. fm Page 148 Thursday, September 14, 2006 3: 11 PM 148 Chapter 3 FIGURE 3. 5 Understanding Laptops and Portable Devices A laptop... platform 4 831 xc 03. fm Page 157 Thursday, September 14, 2006 3: 11 PM Understanding Laptop Architecture 157 Finally, PCMCIA version 3 (PCMCIA 5.0) increased the bus width to 32 -bit and the bus speed from 8MHz to a maximum of 33 MHz In addition, the new CardBus adapters used PCI-like access methods, and the throughput speeds increased dramatically (at the time this text was written, speeds up to 132 Mbps were...4 831 xc 03. fm Page 139 Thursday, September 14, 2006 3: 11 PM Chapter 3 Understanding Laptops and Portable Devices THE FOLLOWING COMPTIA A+ ESSENTIALS EXAM OBJECTIVES ARE COVERED IN THIS CHAPTER: 2.1 Identify the fundamental principles of using laptops and portable devices... outside of the case Mini PCI is functionally identical to the PCI version 2.2, meaning it’s a 32 -bit, 33 MHz bus with a 3. 3V-powered connection It also supports bus mastering and DMA There are three different Mini PCI form factors: Type I, Type II, and Type III The size and connector types are listed in Table 3. 2 TABLE 3. 2 Mini PCI Form Factors Type Connector Size IA 100-pin, stacking 7.5 × 70 × 45 millimeters... square of plastic (usually a very dark maroon) and can typically be found on the front of a PC or on the side of a laptop or portable Figure 3. 11 shows an example of an infrared port 4 831 xc 03. fm Page 160 Thursday, September 14, 2006 3: 11 PM 160 Chapter 3 FIGURE 3. 11 Understanding Laptops and Portable Devices An infrared port Infrared ports send and receive data at a very slow rate (maximum speed on... One of the original problems with LCD displays, and a continuing problem with cheaper versions, is that they have low ratios A display with a low ratio 4 831 xc 03. fm Page 1 53 Thursday, September 14, 2006 3: 11 PM Understanding Laptop Architecture 1 53 won’t show a “true black” very well, and the other colors will look washed out when you have a light source nearby Try to use the device in full sunshine,... the motherboard The same standards that apply to desktop memory compatibility apply to laptops, such as PC2700, PC3200, DDR2, and so forth Current DDR and DDR2 technologies allow you to get SoDIMMS up to 2GB in size FIGURE 3. 2 144-pin SoDIMM 4 831 xc 03. fm Page 147 Thursday, September 14, 2006 3: 11 PM Understanding Laptop Architecture 147 MicroDIMM The newest and smallest RAM form factor is the MicroDIMM... preventative maintenance on laptop computers 4 831 xc 03. fm Page 142 Thursday, September 14, 2006 3: 11 PM 142 Chapter 3 Understanding Laptops and Portable Devices Understanding Laptop Architecture Laptops are similar to desktop computers in architecture in that they contain many parts that perform similar functions However, the parts that make up a laptop are completely different from those in desktop computers... laptop is considerable This is not to say that a laptop can’t outperform a desktop, it’s just that the “bang for the buck” factor is higher in a desktop 4 831 xc 03. fm Page 1 43 Thursday, September 14, 2006 3: 11 PM Understanding Laptop Architecture 1 43 Expandability Because desktop computers were designed to be modular, their capabilities can be upgraded quite easily It is next to impossible to upgrade . PC. 4 831 x.book Page 137 Tuesday, September 12, 2006 11:59 AM 4 831 x.book Page 138 Tuesday, September 12, 2006 11:59 AM Chapter 3 Understanding Laptops and Portable Devices THE FOLLOWING COMPTIA. manufacturer’s trademark D. Parity 4 831 x.book Page 133 Tuesday, September 12, 2006 11:59 AM 134 Chapter 2  Effectively Working with Personal Computer Components 13. Display devices can be connected. drives are designed to work only with a specific model. 4 831 xc 03. fm Page 1 43 Thursday, September 14, 2006 3: 11 PM 144 Chapter 3  Understanding Laptops and Portable Devices repairing