MORE ABOUT PC HARDWARE

MORE ABOUT PC HARDWARE You may think that your PC really doesn’t roar to life until Windows loads. Actually, the PC has a lot of work to do to get to that moment, as you already learned in the section “What Happens When a PC Boots Up.” Then, as you’ll learn in a moment when reading about the role of the operating system, you’ll see that Windows takes over control of your PC once it does load. So what controls the PC from that first push of the power button to the instant the hourglass on the desktop disappears? Something, after all, has to shepherd all those devices like your keyboard, display, and hard drive into service. That something is the BIOS, located on a chip on the motherboard that awakens when power is first supplied to the motherboard after the PC is switched on. Once awake, the BIOS performs an initial inventory of all hardware connected to the PC and manages routines that help bring the hardware online so that the PC bootup process runs smoothly and Windows can indeed load. In the process of Windows loading, Windows looks to the BIOS for information about that hardware and divides it between the PNP vs. non-PNP hardware explained earlier in this chapter. BIOS and How Hardware Connects to the PC When you first install—or reinstall—a troubled device to a PC, the device first communicates with the BIOS, which has the job of fitting it into its master schedule of the other hardware resources. If the BIOS for some reason—the BIOS has been corrupted, the motherboard is damaged, or the hardware is defective, for example—cannot see the device you’ve installed or doesn’t recognize the connection type the device is connected to, the device will not work. In this respect, the BIOS is the first hurdle you have to pass in working with your hardware. Becoming Familiar with Your BIOS Make sure you become familiar with your BIOS, especially the settings you can enable/disable or alter within it, before you get too deeply into a situation that requires you to understand the BIOS. The BIOS can only be accessed by you when the PC is first started. The initial bootup display includes a message stating something like Press to enter Setup. The exact key or combination of keys you need to press depends on the make and model of your PC. Often, this is the Delete key. Once pressed, the system should bring up the BIOS configuration window, sometimes called CMOS Setup. Your available options depend on the make and age of your BIOS, but you should see a menu of categories like these: Standard Settings This category includes date and time settings, drives connected, and basic hardware found. Advanced Settings Advanced settings include whether to look at the floppy drive to see if a boot disk is present before booting off the hard drive, cache options, and memory tests. Bus Settings This category provides configurable options for tweaking performance regarding the hardware installed into the expansion bus slots. Integrated Peripherals This section contains information on whether certain hardware devices and connectors are enabled or disabled, including the USB controller, drive controllers, and the serial and parallel ports. Power Management This section contains options for setting or disabling power management features to reduce the power supplied to certain hardware components (monitor, drives, and so on) when the PC is not in active use. You can use PC information sites such as PC Guide (www.pcguide.com) and PCMechanic (www.pcmechanic.com) to learn more about these BIOS options. Rooting Out the Problem: Troubleshooting Basics A good PC technician is two parts sleuth, one part smart user, and two parts person desperate to get the current problem resolved so he or she can get back to work or play. It’s how much those first three parts can overcome the final two parts that can ensure your success. One of the tools a good sleuth has at his or her disposal is the knowledge of the most likely circumstances surrounding a mystery, based on things like statistical averages and past experience. So a PC sleuth should know that some of the most common causes of PC problems include • Corrupted, incorrect, or bad driver for a device • Incomplete or bad upgrade • Poorly behaved program just installed • Loose or bad cables and connectors • Corrupted program or program installation • A temporary problem that can be resolved by a simple restart of your PC Using this information, a PC detective would • Check and update drivers. • Recheck an upgrade or installation and try to repair it, if applicable. • Check power and cables for looseness or other issues. • Uninstall and reinstall problem programs. • Restart the PC to see if the situation resolves. Rules of the Road Every troubleshooter, experienced or not, has to follow certain basic rules in working with a PC. Here are 10 of the most important rules you need to follow as you work: 1. Work with adequate lighting. 2. Avoid making snap assumptions. 3. Before you proceed, make certain your data is protected. If you can reach your files and folders, copy or back them up first. If you have to troubleshoot to reach that point, do it ASAP. 4. Before assuming a device is broken, check to be sure it’s properly connected and plugged into a viable power source. 5. Always check to be sure connections and cables are secure and in good shape. Lots of crimping or gouging of the cable, for example, means you should replace the cable. 6. If you absolutely don’t know what to do, don’t do anything unless you’re sure you can back out of it again. 7. Never work inside your PC case with the power connected; the PC must be turned off and the power cord removed from the back of the PC. 8. Never work inside your PC case without being properly grounded using something like an anti-static wrist strap. 9. Never think, “If it doesn’t fit, force it.” If something doesn’t fit, it’s usually being installed improperly or is of the wrong connection type. 10. Don’t forget to read the instructions. Some of them may be badly written, but they aren’t optional. The manufacturer’s web site may offer better help. Table 11.1: PC Hardware Wattage Requirements Device Typical Wattage Required to Operate CD drive (48x) 7–30 watts (Depends on the CD formats supported.) CPU 18–50 watts (Depends on the CPU type and age; a Pentium III often takes 20–30 watts, while some Athlons require 40 watts or more.) Fans Variable; a case fan often needs 12 watts. Floppy drive 4–5 watts Hard drive (IDE/ATA) 5–20 watts per drive (Often, the higher the drive RPM, the higher the wattage used.) Memory 10 watts per 128MB (some higher, some lower) Motherboard (bare) 20–35 watts Network adapter 4–5 watts SCSI host adapter 20–30 watts Sound (card) adapter (PCI) 5–20 watts Video adapter (AGP) 18–35 watts Video adapter (PCI) 4–15 watts These are rough estimates; check the technical specifications for your devices, which are usually available in the product documentation. The following are the most common causes for PC overheating: • Blocked intake and exhaust vents • Operating the PC in a very warm environment • Dirty or malfunctioning internal fans • Heavy dust accumulation on internal components • Overcrowding of equipment within the case • Adding several “hot” components without augmenting internal cooling • Overclocking (the process of changing hardware settings to “push” hardware beyond its rated speed/operation) Symptoms of Overheating Overheating can actually cause some rather bizarre and not-easily-explained phenomena. Here are just some of the symptoms you might see with either acute one-time or chronic overheating: • A PC that was operating fine when you first turned it on begins to develop increasing problems. For example, you type one thing but the monitor displays another, opening or saving files to a disk gives you drive errors, or hardware “disappears.” A restart of the PC does little or no good. • You place your hand near an exhaust point, such as at the location of the power supply fan, and notice little or no air being pushed out against your hand. Under ideal conditions, the fan output here isn’t exactly robust, but you should feel a steady flow of warm air. • If you turn the PC on, it appears to start normally and then resets itself after a short period of time, usually the time it takes for the PC to warm up. • You notice parts of the case, especially where drives are located or the side where the motherboard sits, become extremely warm to the touch. • You go inside your system—with power disconnected and properly grounded—and note that components are (or almost are) too hot to touch. • There may be a smell—often a compound of smells related to overheated components, grease, and dust—that may or may not seem like burning. • You receive an on-screen warning about internal temperature. This is a feature with some motherboards and accessories you may add, but not available or enabled on every system. Common Symptoms and Their Culprits When PC performance begins to sag, you can usually feel it, even instinctively. A few of the most frequently noted symptoms are • Prolonged time between the moment you press the power button and the time Windows loads (or reloads) • Sluggish shutdowns • Slowdown in disk operations, including the opening of file screens through Windows Explorer or the Search feature • Programs taking longer than usual to load • Difficulty in changing your focus among different windows open on your desktop There are so many potentially contributing factors to ailing PC performance that they merit a book of their own. Some of the most common issues responsible for slowdowns include • Poor disk maintenance practices • Poor system organization (You don’t watch what is installed or you don’t remove from your hard drive programs you no longer use or data you no longer need to keep.) • Underpowered or overworked PC (not enough disk space, too little memory, and so on) • Viruses (Remember, many viruses annoy more than destroy.) • Poorly configured or missing Windows page file for virtual memory (explained later in this chapter) • Hardware issues, including bad drivers, device conflicts, or failing (but not quite failed) devices • An imbalance in resources (For example, you’re running many background programs by choice, and the balance of processing power is going to the foreground programs such that you have an imbalanced load. Just like your washing machine, Windows works best and makes less noise when you watch what you load and how you load it.) Table 1-1. PC 99 recommended connector color codes Connector Color Connector Color Analog VGA Blue PS/2-compatible keyboard Purple Audio Line-in Light Blue PS/2-compatible mouse Green Audio Line-out Lime Serial Teal/Turquoise Digital monitor/flat panel White Speaker out/subwoofer Orange IEEE 1394 Grey Right-to-left speaker Brown Microphone Pink USB Black MIDI/gameport Gold Video Out Yellow Parallel Burgundy SCSI, LAN, telephone, etc. Not defined Table 1-2. 8/16/32-bit ISA/PCI standard IRQ assignments IRQ Bus type Typically used by 00 none Non-maskable Interrupt (NMI); system timer 01 none Keyboard port 02 none Programmable Interrupt Controller (PIC); cascade to IRQ 09 03 8/16-bit Communications Port 2 (COM2:) 04 8/16-bit Communications Port 1 (COM1:) 05 8/16-bit Sound card; Printer Port (LPT2:) 06 8/16-bit Floppy Disk Controller 07 8/16-bit Printer Port (LPT1:) 08 none System CMOS/real-time clock 09 8/16-bit Redirected from IRQ 02; network interface 10 16-bit Network interface; USB host controller 11 16-bit Video Adapter; SCSI host adapter 12 16-bit PS/2 mouse port 13 none Numeric Data Processor (math co-processor) 14 16-bit Primary IDE interface 15 16-bit Secondary IDE interface Table 23.1: DOS/Windows Common File Extensions File Extension Association .BAK DOS backup file .BAT DOS file housing a sequence of commands .BMP Windows bit-mapped graphics file .CAB Windows 9x cabinet file .COM DOS command program file .DLL Windows dynamic link library file .DOC Text document file (usually Microsoft Word) .EXE DOS executable program .GRP Windows 3x program group file .HTM Hypertext markup language file .ICO Windows 3x icon file .INI DOS Windows initialization file .SYS DOS system driver/hardware configuration file .TMP Temporary file .TXT Text file created by DOS or the Windows text editor .VXD Virtual device driver file Symbol Definition Kb Kilobit — 1,024 bits KB Kilobyte — 1,024 bytes Mb Megabit — 1,048,576 bits MB Megabyte — 1,048,576 bytes Gb Gigabit — 1,073,741,824 bits GB Gigabyte — 1,073,741,824 bytes