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Text File | 1994-09-21 | 56KB | 992 lines

REDUCE YOUR RISKS To reduce your need for computer repairs, remember the following tips. Hot weather If possible, avoid using the computer in hot weather. When the room's temperature rises above 93 degrees, the fan inside the computer has trouble cooling the computer sufficiently. Wait until the weather is cooler (such as late at night), or buy an air conditioner, or buy a window fan to put on your desk and aim at the computer, or use the computer for just an hour at a time (so that the computer doesn't have a chance to overheat). Another problem in the summer is electrical brownouts, where air conditioners in your house or community consume so much electricity that not enough voltage gets to your computer. Transporting your computer Some parts inside the computer are delicate. Don't bang or shake the computer! If you need to move the computer to a different location, be gentle! And before moving the computer, make backups: copy everything important from the computer's hard disk onto floppy disks. For example, copy all the documents, database files, and spreadsheets you created, and also copy AUTOEXEC.BAT, CONFIG.SYS, and COMMAND.COM. Transporting by hand If you must move the computer to a different desk or building, be very gentle when you pick up the computer, carry it, and plop it down. Be especially gentle when walking on stairs and through doorways. Transporting by car If you're transporting your computer by car, put the computer in the front seat, put a blanket underneath the computer, and drive slowly (especially around curves and over bumps). Do not put the computer in the trunk, since the trunk has the least protection against bumps. If you have the original padded box that the computer came in, put the computer in it, since the box's padding is professionally designed to protect against bumps. Transporting by air If you're transporting your computer by air, avoid checking the computer through the baggage department. The baggage handlers will treat the computer as if it were a football, and their ``forward pass'' will make you pissed. Instead, try to carry the computer with you on the plane, if the computer's small enough to fit under your seat or in the overhead bin. If the whole computer won't fit, carry as much of the computer as will fit (the keyboard, the monitor, or the system unit?) and check the rest as baggage. If you must check the computer as baggage, use the original padded box that the computer came in, or else find a giant box and put lots and lots and lots of padding material in it. When going through airport security, it's okay to let the security guards X-ray your computer and disks. Do not carry the computer and disks in your hands as you go through the metal detector, since the magnetic field might erase your disks. For best results, just tell the guards you have a computer and disks; instead of running the computer and disks through detection equipment, the guards will inspect your stuff personally. To make sure your computer doesn't contain a bomb, the guards might ask you to unscrew the computer or prove that it actually works. If your computer's a laptop and you need to prove it works, make sure you brought your batteries ___ and make sure the batteries are fully charged! Since airport rules about baggage and security continually change, ask your airport for details before taking a trip. Parking the head If your computer is ancient (an 8088 or an early-vintage 286), it might have come with a program called SHIPDISK or PARK. That program is not part of DOS; instead, the program comes on a floppy disk called UTILITIES or DIAGNOSTICS. That program does an activity called parking the head: it moves the hard drive's head to the disk's innermost track, where there's no data. Then if the head accidentally bangs against the disk, it won't scrape off any data. If your computer came with a SHIPDISK or PARK program, run it before you transport the computer. After your journey, when you turn the computer back on, the head automatically unparks itself and reads whatever data you wish. If your computer did not come with a SHIPDISK or PARK program, don't worry about it. Modern disk drives park the head automatically whenever you turn the power off. For older disk drives, handling the computer gently is more important than parking the head. In any case, do not borrow a SHIPDISK or PARK program from a friend, since somebody else's program might assume the hard drive has a different number of tracks. Repair shops use an extra-fancy PARK program: it tests the hard drive, determines how many tracks are on it, and then moves the head to the correct innermost track. Saving your work When you're typing lots of info into a word-processing program or spreadsheet, the stuff you've typed is in the computer's RAM. Every ten minutes, copy that info onto the hard disk, by giving the SAVE command. (To learn how to give the SAVE command, read my word-processing and spreadsheet chapters.) That way, if the computer breaks down (or you make a boo-boo), the hard disk will contain a copy of most of your work, and you'll need to retype at most ten minutes worth. Split into chapters If you're using a word-processing program to type a book, split the book into chapters. Make each chapter be a separate file. That way, if something goes wrong with the file, you've lost just one chapter instead of the whole book. Disk space Make sure your hard disk isn't full. Make sure your hard disk has at least 2 megabytes of unused space on it. To find out how much unused space is on your hard disk, say: C:\>dir That makes the computer list the files in your root directory and also tell you how many bytes are free. If the number of free bytes is less than 2,000,000, you have less than two megabytes of free space, and you're in a dangerous situation! Erase some files, so that the number of free bytes becomes more than 2,000,000. If the number of free bytes is less than 2,000,000, some of your programs might act unreliably, because the programmers who wrote those programs were too lazy to check whether the programs would work on a hard disk that's so full. Some of those programs try to create temporary files on your hard disk; but if your hard disk is nearly full, the temporary files won't fit, and so the computer will gripe at you, act nuts, and seem broken. If possible, erase enough unimportant files from your hard disk so that 5 megabytes are free. That ensures even the biggest temporary files will fit. It also helps DOS act faster, since DOS doesn't have to look so hard to find where your hard disk's free megabytes are. Windows For Windows to run reasonably fast, at least 10 megabytes should be free, since Windows tries to create lots of temporary files. Overly fancy software Avoid buying and using software that adds many lines to your CONFIG.SYS and AUTOEXEC.BAT files. The longer and more complicated your CONFIG.SYS and AUTOEXEC.BAT files are, the greater the chance that something will go wrong with them, and your computer will refuse to boot up. Even if each line in your CONFIG.SYS and AUTOEXEC.BAT file looks fine, the lines may conflict with each other. Keep your AUTOEXEC.BAT file simple, so that when you turn the computer on, the computer says: C:\> Do not make the computer automatically go into Windows or the DOS shell or a menu. Instead, get in the habit of manually typing ``win'' to go into Windows, ``dosshell'' to go into the DOS shell, a command such as ``menu'' to go into a menu, or a command such as ``do wp'' to go into Word Perfect (by using the DO.BAT trick I explained on page 130). If you make the mistake of setting up your computer to automatically go into Windows, and Windows someday stops working properly, the computer won't boot at all. You'll be in a real mess! Also, if the computer automatically goes into Windows, and you try to use Windows as a menu system to choose which non-Windows software to run, that non-Windows software will run slower and less reliably than if you ran the software directly without going through Windows. Avoid compression If possible, avoid using programs such as Stacker, which attempts to squeeze extra megabytes of data onto your hard disk by using compression codes. Although such programs usually work, they're very delicate: if you accidentally erase those programs (or erase or modify the CONFIG.SYS file that mentions them), you won't be able to use any of the data on your hard disk! Judging from the phone calls I receive, I get the impression that 90% of all the people who use Stacker are happy, and the other 10% lose all their data. DOS 6 headaches DOS 6 includes three routines that are dangerously unreliable: Double Space, Smart Drive, and Mem Maker. If you avoid those routines, DOS 6 is reliable; if you use those routines, DOS 6 can get quite nasty, which is why many companies have banned DOS 6! Double Space Like Stacker, Double Space attempts to squeeze extra megabytes of data onto your hard disk by using compression codes. It has the same headaches. Smart Drive To make your hard drive seem faster, the version of Smart Drive included with DOS 6 and Windows 3.1 tries to make RAM imitate your hard disk, so when you tell the computer to write to the hard disk the computer writes to RAM instead, which is faster. It writes to a part of the RAM called the disk cache. Later, when you don't seem to be using the computer and seem to be just scratching your head wondering what to do next, Smart Drive copies the disk cache's contents to the hard disk. But what if you turn off the computer (or the computer's hardware or software malfunctions) before Smart Drive gets around to copying the disk cache's contents to the hard disk? Then the hard disk will contain less info than it's supposed to. When you restart the computer, Double Space will notice that info is missing from the hard disk; then Double Space will get confused and refuse to operate. Suddenly, your whole hard disk has become useless! If you ignore my advice and decide to use Smart Drive anyway, get in the habit of waiting 10 seconds before turning your computer off. The 10-second wait makes Smart Drive realize you're doing nothing, so Smart Drive copies the disk cache's contents to the hard disk. Another problem is that when Smart Drive suddenly decides to burst into action and write to your hard disk, it can interrupt the computer from handling any modem or fax transmissions that are in progress. Also, Smart Drive confuses the typical human, who doesn't understand why the hard-drive light goes on at strange times instead of when the human said to write to the hard disk. Mem Maker Mem Maker tries to modify your CONFIG.SYS and AUTOEXEC.BAT files so specific programs get put into specific places in RAM. It works fine ___ until you buy an extra program that doesn't fit into the RAM-memory scheme created by Mem Maker. Then you must go through the hassle of telling Mem Maker to reanalyze the situation and put the programs into different places instead. To avoid those hassles, avoid using Double Space, Smart Drive, and Mem Maker. Then DOS 6 works great! DOS 6.2 In DOS 6.2, Microsoft improved Double Space, Smart Drive, and Mem Maker so that they cause problems less frequently and less severely. Nevertheless, those three routines can still cause the same kinds of problems, and I still recommend avoiding them. After inventing DOS 6 and 6.2, Microsoft was sued by a company called Stac Electronics, which said Double Space contained routines that Microsoft illegally copied from Stacker. To duck the suit, Microsoft invented DOS 6.21 (which omits Double Space) and then DOS 6.22 (which replaces Double Space by a similar routine called Disk Space (and has the same problems). GENERAL PRINCIPLES OF REPAIR Here are the general principles you need to know, to repair a computer. teachers, your friends, and me. You can phone me day or night, 24 hours, at 617-666-2666; I'm almost always in, and I sleep only lightly. Most computers come with a one-year warranty. If your computer gives you trouble during that first year, make use of the warranty: get the free help you're entitled to from your dealer. If your ``dealer'' is a general-purpose department store that doesn't specialize in computers, the store might tell you to phone the computer's manufacturer. For tough software questions, the dealer might tell you to phone the software's publisher. Most computers come with a 30-day money-back guarantee. If the computer is giving you lots of headaches during the first 30 days, just return it! Chuck If the broken part is cheap, don't fix it: chuck it! For example, if one of the keys on your keyboard stops working, don't bother trying to fix that key; instead, buy a new keyboard. A new keyboard costs just $35. Fixing one key on a keyboard costs many hours of labor and is silly. If a 10-megabyte hard disk stops working, and you can't fix the problem in an hour or so, just give up and buy a new hard disk, since 10-megabyte hard disks are obsolete anyway. Today, 10 megabytes aren't worth much; the price difference between a 30-megabyte drive and a 40-megabyte drive is about $10. Observe Read the screen. Often, the screen will display an error message that tells you what the problem is. If the message flashes on the screen too briefly for you to read, try pressing the computer's PAUSE key as soon as the message appears. The PAUSE key makes the message stay on the screen for you to read. When you finish reading the message, press the ENTER key. If you're having trouble with your printer, and your printer is modern enough to have a built-in screen, read the messages on that screen too. Check the lights. Look at the blinking lights on the front of the computer and the front of the printer; see if the correct ones are glowing. Also notice whether the monitor's POWER light is glowing. Check the switches. Check the ON-OFF switches for the computer, monitor, and printer: make sure they're all flipped on. If your computer equipment is plugged into a power strip, make sure the strip's ON-OFF switch is turned on. Check the monitor's brightness and contrast knobs, to make sure they're turned to the normal (middle) position. If you have a dot-matrix printer, make sure the paper is feeding correctly, and make sure you've put into the correct position the lever that lets you choose between tractor feed and friction feed. Check the cables that run out of the computer. They run to the monitor, printer, keyboard, mouse, and wall. Make sure they're all plugged tightly into their sockets. To make sure they're plugged in tight, unplug them and then plug them back in again. (To be safe, turn the computer equipment off before fiddling with the cables.) Many monitor and printer problems are caused just by loose cables. Make sure each cable is plugged into the correct socket. Examine the back of your computer, printer, monitor, and modem: if you see two sockets that look identical, try plugging the cable into the other socket. For example, the cable from your printer might fit into two identical sockets at the back of the computer (LPT1 and LPT2); the cable from your phone system might fit into two identical sockets at the back of your modem (LINE and PHONE); the cable from your monitor might fit into two identical sockets at the back of the computer (COLOR and MONOCHROME). Strip When analyzing a hardware problem, run no software except DOS and diagnostics. For example, if you're experiencing a problem while using a word-processing program, spreadsheet, database, game, Windows, or some other software, exit from whatever software you're in. Then turn off your printer, computer, and all your other equipment, so the RAM chips inside each device get erased and forget that software. Then turn the computer back on. Try to make the screen say: C:\> If you succeed, your screen is working fine. Then say ``dir''. If that makes the computer show you a directory of all the files in your hard disk's root directory, your hard disk is working fine. Then turn on the printer and say ``dir>prn''. If that makes the computer copy the directory onto paper, your printer's working fine. (On some laser printers, such as the Hewlett Packard Laserjet 2, you need to manually eject the paper: press the printer's ON LINE button, then the FORM FEED button, then the ON LINE button again.) If your computer, monitor, hard drive, and printer pass all those tests, your hardware is basically fine; and so the problem you were having was probably caused by software rather than hardware. For example, maybe you forgot to tell your software what kind of printer and monitor you bought. If you wish to test your hardware more thoroughly, you can give additional DOS commands. Better yet, run diagnostic software such as Check It and Norton Disk Doctor. They test your computer and tell you what's wrong. To get Norton Disk Doctor, buy either the software collection called Norton Utilities or the software collection called Norton Desktop for DOS. The newest version of Norton Utilities, which is version 7, also includes diagnostic routines for checking your motherboard and other parts of your computer. BOOTING PROBLEMS Turning the computer on is called booting. As soon as you turn the computer on, you may experience one of these problems. Lots of beeping Problem When you turn the computer on, you just hear a very long beep or very many little beeps. Cause The fault probably lies in your motherboard or power supply (AC/DC transformer). For example, the motherboard's circuitry might have a short or a break, or one of the chips might have become defective. Cure Turn the computer off immediately, and take it in to a repair shop. No video Problem When you turn the computer on, the screen is entirely blank, so you don't even see the cursor. Cause The fault probably lies in your monitor or its cables. Cure Make sure the monitor is turned on, its contrast and brightness knobs are turned up, and its two cables (to the power and to the computer's video card) are both plugged in tight. (Those cables can easily come loose.) If the monitor has a power-on light, check whether that light is glowing. If it doesn't glow, the monitor isn't getting any power (because the on-off button is in the wrong position, or the power cable is loose, or the monitor is broken). If the monitor is indeed broken, do not open the monitor, which contains high voltages even when turned off; instead, return the monitor to your dealer. If you've fiddled with the knobs and cables and the power-on light is glowing but the screen is still blank, boot up the computer again, and look at the screen carefully: maybe a message did flash on the screen quickly? If a message did appear, fix whatever problem the message talks about. (If the message was too fast for you to read, boot up again and quickly hit the PAUSE key as soon as the message appears, then press ENTER when you finish reading the message.) If the message appears but does not mention a problem, you're in the middle of a program that has crashed (stopped working), so the fault lies in software mentioned in CONFIG.SYS or AUTOEXEC.BAT or COMMAND.COM or some other software involved in booting; to explore further, put a DOS disk in drive A and reboot. If absolutely no message appears on the screen during the booting process, so that the screen is entirely blank, check the lights on the computer (maybe the computer is turned off or broken) and recheck the cables that go to the monitor. If you still have no luck, the fault is probably in the video card inside the computer, though it might be on the motherboard or in the middle of the video cable that goes from the video card to the monitor. At this point, before you run out and buy new hardware, try swapping with a friend whose computer has the same kind of video as yours (for example, you both have VGA): try swapping monitors, then video cables, then video cards, while making notes about which combinations work, until you finally discover which piece of hardware is causing the failure. Then replace that hardware, and you're done! SETUP Problem When you turn the computer on, the computer gripes by printing a message such as ``Invalid configuration specification: run SETUP.'' Cause Your computer's CPU is fast. It's a 286, 386, 486, or Pentium. It's not an 8088. Each fast computer contains a battery that feeds power to the CMOS RAM. That CMOS RAM tries to keep track of the date, time, how many megabytes of RAM you've bought, how you want the RAM used, what kind of video you bought, and what kind of disk drives you bought. If the information in the CMOS RAM is wrong, the computer usually gripes during bootup by printing a message such as, ``Invalid configuration specification: run SETUP.'' Cure Try running the CMOS SETUP program, which asks you questions and then stores your answers to the CMOS RAM. To find out how to run that program, ask your dealer. If your computer's CPU is an old 286, the CMOS SETUP program comes on a floppy disk. That disk is not one of the MS-DOS disks but rather is a separate utility disk. If your computer is a newer 286 or a 386 or 486, the CMOS SETUP program does not come on a floppy disk. Instead, the CMOS SETUP program hides in a ROM chip inside your computer and is run when you hit a ``special key'' during the bootup's RAM test. That ``special key'' is usually either the DELETE key or the Esc key or the F1 key; to find out what the ``special key'' is on your computer, read your computer's manual or ask your dealer. Once the CMOS SETUP program starts running, it asks you lots of questions. For each question, it also shows you what it guesses the answer is. (The computer's guesses are based on what information the computer was fed before.) On a sheet of paper, jot down what the computer's guesses are. That sheet of paper will turn out to be very useful! Some of those questions are easy to answer (such as the date and time). A harder question is when the computer asks you to input your hard-drive type number. The answer is a code number from 1 to 47, which you must get from your dealer. (If your dealer doesn't know the answer, phone the computer's manufacturer. If the manufacturer doesn't know the answer, look inside the computer at the hard drive; stamped on the drive, you'll see the drive's manufacturer and model number; then phone the drive's manufacturer, tell the manufacturer which model number you bought, and ask for the corresponding hard-drive type number.) If the answer is 47, the computer then asks you technical questions about your drive; get the answers from your dealer (or drive's manufacturer). If you don't know how to answer a question, and you can't reach your dealer for help, just move ahead to the next question, and leave intact the answer that the computer guessed. After you've finished the questionnaire, the computer will automatically reboot. If the computer gripes again, either you answered the questions wrong or else the battery ran out ___ so that the computer forgot your answers! In fact, the most popular reason why the computer asks you to run the CMOS SETUP program is that the battery ran out. (The battery usually lasts 1-4 years.) To solve the problem, first make sure you've jotted down the computer's guesses, then replace the battery, which is usually just to the left of the big power supply inside the computer. If you're lucky, the ``battery'' is actually a bunch of four AA flashlight batteries that you can buy in any hardware store. If you're unlucky, the battery is a round silver disk, made of lithium, like the battery in a digital watch: to get a replacement, see your dealer. After replacing the battery, run the CMOS SETUP program again, and feed it the data that you jotted down. That's the procedure. If you're ambitious, try it. If you're a beginner, save yourself the agony by just taking the whole computer to your dealer: let the dealer diddle with the CMOS SETUP program and batteries for you. Whenever you upgrade your computer with a better disk drive or video card or extra RAM, you must run the CMOS SETUP program again to tell the computer what you bought. Non-system disk Problem The computer says ``Non-system disk or disk error''. Cause The computer is having trouble finding the hidden system files. (If you're using MS-DOS, the hidden system files are called IO.SYS and MSDOS.SYS. If you're using PC-DOS instead, the hidden system files are called IBMIO.COM and IBMDOS.COM.) Those hidden system files are supposed to be on your hard disk. One reason why you might get that error message is that those hidden system files are missing from your hard disk ___ because that disk is new and hasn't been formatted yet, or because when you formatted the disk you forgot to say ``/s'' at the end of the format command, or because you accidentally erased those files. A more common reason for getting that error message is: you accidentally put a floppy disk into drive A! When the computer boots, it looks at that floppy disk instead of your hard disk, and gripes because it can't find those system files on your floppy disk. Cure Remove any disk from drive A. Turn the computer off, wait until the computer quiets down, then turn the computer back on. If the computer still says ``Non-system disk or disk error'', find the floppy disks that DOS came on and try again to install DOS onto your hard disk. Command interpreter Problem The computer says ``Bad or missing command interpreter''. Cause The computer is having trouble finding and using your COMMAND.COM file. That file is supposed to be in your hard disk's root directory ___ unless your CONFIG.SYS file contains a ``shell='' line that tells the computer to look elsewhere. Probably you accidentally erased COMMAND.COM, or accidentally fiddled with your CONFIG.SYS file, or accidentally put a floppy disk in drive A (which makes the computer look for COMMAND.COM on your floppy disk instead of your hard disk), or your COMMAND.COM file came from a different version of DOS than your hidden files. Cure Remove any disk from drive A, then try again to boot. If you get the same error, put into drive A the main floppy disk that DOS came on, and reboot again. (Make sure you use the original DOS floppy, not a copy. Make sure you use the same version of DOS as before; don't switch versions. If you're using DOS 4, insert the disk labeled ``install''. If you're using DOS 5 or 6, insert the disk lableled ``setup''. If a disk is labeled ``DOS 5 Upgrade'' instead of just ``DOS 5'', that disk isn't bootable; buy or borrow a disk labeled ``DOS 5 ___ Setup''.) Then try to copy DOS onto your hard disk again. If you had accidentally erased COMMAND.COM from your hard disk, you probably also erased CONFIG.SYS and AUTOEXEC.BAT, and you may need to reconstruct those files. SHARE Problem The computer says, ``Warning ___ SHARE should be loaded for large media''. Cause You're using DOS 4, and it's installed incorrectly. Cure Your best bet is to upgrade to DOS 5 or 6, which will make that message go away. If you refuse to upgrade, here's another way to make sure that message disappears: put the SHARE.EXE program into your hard disk's root directory and also your hard disk's DOS directory. (The SHARE.EXE program comes on the original DOS 4 floppy disks and is probably already in your hard disk's DOS directory. To copy it to the root directory, just give the copy command.) KEYBOARD PROBLEMS Your keyboard might seem broken. Here's what to do. Wet keyboard Problem You recently spilled water, coffee, soda, or some other drink into the keyboard, and now the computer refuses to react properly to your keyboard. Cause The liquid in the keyboard is causing an electrical short-circuit. Cure Turn off the computer. Turn the keyboard upside-down for a few minutes, in the hope that some of the liquid drips out. Then let the keyboard rest a few hours, until the remaining liquid in it dries. Try again to use the keyboard. It will probably work fine. If not, look for one of the symptoms below. Dead keyboard Problem When you press letters on the keyboard, those letters do not appear on the screen. Cause Either the keyboard is improperly hooked up, or the computer is overheating, or you're running a frustrated program (which is ignoring what you type or waiting until a special event happens). For example, the program might be waiting for the printer to print, or the disk drive to manipulate a file, or the CPU to finish a computation, or your finger to hit a special key or give a special command. Cure First, try getting out of any program you've been running: press the Esc key (which might let you escape from the program) or the F1 key (which might display a helpful message) or ENTER (which might move on to the next screenful of information) or Ctrl with C (which might abort the program) or Ctrl with Break. If the screen is unchanged and the computer still ignores your typing, reboot the computer; then watch the screen for error messages such as ``301'' (which means a defective keyboard), ``201'' (which means defective RAM chips), or ``1701'' (which means a defective hard drive). If the keyboard seems to be ``defective'', it might just be unplugged from the computer. Make sure the cable from the keyboard is plugged tightly into the computer. To make sure it's tight, unplug it and then plug it back in again. If you stand behind the original IBM PC (instead of a newer computer), you'll see two sockets that look identical. The left one (which usually has the word ``Keyboard'' and a ``K'' next to it) is for the keyboard cable; the other is for a cassette tape recorder (which nobody uses). Underneath a keyboard built by a clone company, you might see a switch marked ``XT - AT'' (or simply ``X -A''). Put that switch in the XT (or X) position if your computer is an IBM XT (or an original IBM PC or any computer containing an 8088 CPU). Put the switch in the AT (or A) position if your computer is an IBM AT (or any computer containing a 286, 386, or 486 CPU). If you don't see such a switch, make sure your keyboard was designed to work with your computer. If fiddling with the cable and the XT-AT switch doesn't solve your problem, reboot the computer and see what happens. Maybe you'll get lucky. Maybe some part of the computer is overheating. Here's how to find out. . . . Turn the computer off. Leave it off for at least an hour, so it cools down. Then turn the computer back on. Try to get to a C prompt. After the C prompt, type a letter (such as x) and notice whether the x appears on the screen. If the x appears, don't bother pressing the ENTER key afterwards; instead, walk away from the computer for two hours ___ leave the computer turned on ___ then come back two hours later and try typing another letter (such as y). If the y doesn't appear, you know that the computer ``died'' sometime after you typed x but before you typed y; and since during that time the computer was just sitting there doing nothing except being turned on and getting warmer, you know the problem was caused by overheating: some part inside the computer is failing as the internal temperature rises. That part could be a RAM chip, BIOS chip, or otherwise. Since that part isn't tolerant enough of heat, it must be replaced: take the computer in for repair. That kind of test ___ where you leave the computer on for several hours to see what happens as the computer warms up ___ is called letting the computer cook. During the cooking, if smoke comes out of one of the computer's parts, that part is said to have fried. If the part has also blackened, it's said to have been fried, Cajun style. That same jargon applies to humans: when a programmer has been working hard on a project for many hours and is totally exhausted and can no longer think straight, the programmer says, ``I'm burnt out. My brain is fried.'' Common solutions are sleep and pizza (``getting some z's & 'za''). When computers are manufactured, the last step in the assembly line is to leave the computer turned on a long time, to let the computer cook and make sure it still works when hot. A top-notch manufacturer leaves the computer on for 2 days (48 hours) or even 3 days (72 hours), while continually testing the computer to make sure no parts fail. That part of the assembly line is called burning in the computer; many top-notch manufacturers do 72-hour burn in. Sluggish key Problem After pressing one of the keys, it doesn't pop back up fast enough. Cause Probably there's dirt under the key. The ``dirt'' is probably dust or coagulated drinks (such as Coke or coffee). Cure If many keys are sluggish, don't bother trying to fix them all. Just buy a new keyboard (for about $30). If just one or two keys are sluggish, here's how to try fixing a sluggish key. . . . Take a paper clip, partly unravel it so it becomes a hook, then use that hook to pry the up the key, until the keycap pops off. Clean the part of the keyboard that was under that keycap: blow away the dust, and wipe away grime (such as coagulated drinks). With the keycap still off, turn on the computer, and try pressing the plunger that was under the keycap. If the plunger is still sluggish, you haven't cleaned it enough. (Don't try too hard: remember that a new keyboard costs just about $30.) When the plunger works fine, turn off the computer, put the keycap back on, and the key should work fine. Caps Problem While you're typing, each capital letter unexpectedly becomes small, and each small letter becomes capitalized. Cause The SHIFT key or CAPS LOCK key is activated. The culprit is usually the CAPS LOCK key. Probably you activated it by pressing it accidentally when you meant to press a nearby key instead. The CAPS LOCK key stays activated until you deactivate it by pressing it again. Cure Press the CAPS LOCK key (again), then try typing some more, to see whether the problem has gone away. If your keyboard is modern, its top right corner has a CAPS LOCK light. That light glows when the CAPS LOCK key is activated; the light stops glowing when the CAPS LOCK key is deactivated. If pressing the CAPS LOCK key doesn't solve the problem, try jiggling the left SHIFT key, then the right SHIFT key. (Maybe one of those SHIFT keys was accidentally stuck in the down position, because you spilled some soda that got into the keyboard and coagulated and made the SHIFT key too sticky to pop all the way back up.) If playing with the CAPS LOCK and SHIFT keys doesn't immediately solve your problem, try typing a comma and notice what happens. If the screen shows the symbol ``<'' instead of a comma, your SHIFT key is activated. (The CAPS LOCK key has no effect on the comma key, since the CAPS LOCK key affects just letters, not punctuation.) If pressing the comma key makes the screen show a comma, your SHIFT key is not activated, and any problems you have must therefore be caused by the CAPS LOCK key instead. Perhaps the CAPS LOCK key is being activated automatically by the program you're using. (For example, some programs automatically activate the CAPS LOCK key because they want your input to be capitalized.) To find out, exit from the program, reboot the computer, get to a C prompt, and try again to type. If the typing is displayed fine, the ``problem'' was probably caused by just the program you were using ___ perhaps on purpose. In some old Leading Edge Model D computers, the ROM has a defect that occasionally misinterprets the signals from the CAPS LOCK and SHIFT keys. When that happens, just try tapping those keys until the display returns to normal. PRINTER PROBLEMS If you're having trouble printing, the first thing to do is try this experiment. Turn off the computer and the printer (so you can start fresh). When the computer has become quiet, turn it back on; then turn the printer back on. Get out of Windows and any other software you're in, so you have a C prompt, like this: C:\> Then say ``dir>prn'' like this: C:\>dir>prn That's supposed to make the printer print a copy of your directory. Another experment to try is this: C:\>echo abcdefghijklmnopqrstuvwxyz>prn That's supposed to make the printer print the alphabet. If both of those experiments work fine, all your hardware is okay. Any remaining problem is probably just software: for example, you forgot to tell your program or Windows what kind of printer you bought, or you told it incorrectly. If the experiments do not work fine, you're having a hardware problem: the problem lies in your printer, your computer, or the cable connecting them. Here are further details. . . . Incomplete characters Problem Part of each character is missing. For example, for the letter ``A'' you see just the top part of the ``A'', or just the bottom part, or everything except the middle. Cause You're probably using a 9-pin, 24-pin, ink-jet, or daisy-wheel printer, not a laser printer. Some of the pins (or ink jets or daisy petals) are not successfully putting ink onto the paper. Cure If the bottom part of each character is missing, your printer probably uses a ribbon, and the ribbon is too high, so that the bottom pins miss hitting it. Push the ribbon down lower. Read the instructions that came with your printer and ribbon, to find out the correct way to thread the ribbon through your printer. If you're using a daisy-wheel printer, also check whether the daisy-wheel is inserted correctly: try removing it and then reinserting it. If some other part of each character is missing, and you're using a 9-pin or 24-pin printer, probably one of the pins is broken or stuck. Look at the print head, where the pins are. See if one of the pins is missing or broken. If so, consider buying a new print head, but beware: since print heads are not available from discount dealers, you must pay full list price for the print head, and pay almost as much for it as discount dealers charge for a whole new printer! Substitute characters Problem When you tell the printer to print a word, it prints the correct number of characters but prints different letters of the alphabet instead. For example, instead of printing an ``A'', the printer prints a ``B'' or ``C''. Cause In the cable going from the computer to the printer, some of the wires aren't working properly. The cable is probably loose or defective. Cure Turn off the printer. Grab the cable that goes from the computer to the printer, unplug both ends of the cable, then plug both ends in again tightly. Try again to print. If you succeed, the cable was just loose: congratulations, you tightened it! If unplugging and replugging the cable does not solve the problem, then the cable is not just loose: it's probably defective! To prove that it's defective, borrow a cable from a friend and try again. If your friend's cable works with your computer and printer, your original cable was definitely the culprit. Once you've convinced yourself that the problem is the cable, go to a store and buy a new cable. It costs about $8 from discount dealers (such as Staples). It's cheaper to buy a new cable than to fix the old one. If the new cable doesn't solve your problem, try a third cable, since many cables are defective! If none of the three cables solves your problem, the problem is caused by defective circuitry in your printer or in your computer's parallel-printer port. Get together with a friend and try swapping printers, computers, and cables: make notes about which combinations work and which don't. You'll soon discover which computers, cables, and printers work correctly and which ones are defective. Extra characters Problem When using a program (such as a word-processing program), the printer prints a few extra characters at the top of each page. Cause Those extra characters are special codes that the printer should not print. Those codes are supposed to tell the printer how to print. But your printer is misinterpreting those codes. That's because those codes were intended for a different kind of printer. Cure Try again to tell your software which printer you bought. To tell Windows which printer you bought, go to the program manager, then double-click the Main icon, then double-click the Control Panel icon, then double-click the Printers icon, then follow the prompts on the screen. To tell a non-Windows program which printer you bought, read the program's manual: look for the part of the manual that explains ``printer installation & selection & setup''. Misaligned columns Problem When printing a table of numbers or words, the columns wiggle: some of the words and numbers are printed slightly too far to the left or right, even though they looked perfectly aligned on the screen. Cause You're trying to print by using a proportionally spaced font that doesn't match the screen's font. Cure The simplest way to solve the problem is to switch to a monospaced font, such as Courier or Prestige Elite or Gothic or Lineprinter. Since those fonts are monospaced (each character is the same width as every other character), there are no surprises. To switch fonts while using Windows, use your mouse, drag across all the text whose font you wish to switch, then say which font you wish to switch to. Unfortunately, monospaced fonts are ugly. If you insist on using proportionally spaced fonts, remember that when moving from column to column, you should press the TAB key, not the SPACE bar. (In proportionally spaced fonts, the SPACE bar creates a printed space that's too narrow: it's narrower than the space created by the typical digit or letter.) If the TAB key doesn't make the columns your favorite width, customize how TAB key works by adjusting the TAB stops. (In most word-processing programs, you adjust the TAB stops by sliding them on the layout ruler.) Normally, the computer tries to justify your text: it tries to make the right margin straight by inserting extra spaces between the words. But when you're printing a table, those extra spaces can wreck your column alignment. So when typing a table of number, do not tell the computer to justify your text: turn justification OFF. Touching characters Problem When printing on paper, some of the characters bump into each other, so that ``cat'' looks like ``cat''. Cause The computer has fed the printer wrong information about how wide to make the characters and how much space to leave between them. That's because you told the computer wrong info about which printer you're going to use. Cure Tell the computer again which printer you're going to use. For example, suppose you plan to type a document by using your home computer's word-processing program, then copy the document onto a floppy disk, take the floppy disk to your office, and print a final draft on the office's printer. Since you'll be printing the final draft on the office's printer, tell your home computer that you'll be using the office's printer. If you're using Windows, here's how: double-click the Main icon, double-click the Control Panel icon, double-click the Printer icon, click the Add button, then double-click the printer's name. Margins Problem On a sheet of paper, all the printing is too far to the left, or too far to the right, or too far up, or too far down. Cause You forgot to tell the computer about the paper's size, margins, and feed, or you misfed the paper into the printer. Cure Most computer software assumes the paper is 11 inches tall and 8½ inches wide (or slightly wider, if the paper has holes in its sides). The software also assumes that you want 1-inch margins on all four sides (top, bottom, left, and right). If you told the software you have a dot-matrix printer, the software usually assumes you're using pin-feed paper (which has holes in the side); it's also called continuous-feed paper. For ink-jet and laser printers, the software typically assumes you're using friction-feed paper instead (which has no holes). If those assumptions are not correct, tell the software. For example, give a ``margin'', ``page size'', or ``feed'' command to your word-processing software. If you make a mistake about how tall the sheet of paper is, the computer will try to print too many or too few lines per page. The result is creep: on the first page, the printing begins correctly; but on the second page the printing is slightly too low or too high, and on the third page the printing is even more off. To solve a creep problem, revise slightly what you tell the software about how tall the sheet of paper is. For example, if the printing is fine on the first page but an inch too low on the second page, tell the software that each sheet of paper is an inch shorter. On pin-feed paper, the printer can print all the way from the very top of the paper to the very bottom. On friction-feed paper, the printer cannot print at the sheet's very top or very bottom (since the rollers can't grab the paper securely enough while printing there). So on friction-feed paper, the printable area is smaller, as if the paper were shorter. Telling the software wrong information about feed has the same effect as telling the software wrong information about the paper's height: you get creep. So to fix creep, revise what you tell the software about the paper's height or feed. If the software doesn't let you talk about the paper's feed, kill the creep by revising what you say about the paper's height. If you're using a dot-matrix printer that can handle both kinds of paper (pin-feed and friction-feed), you'll solve most creep problems by choosing pin-feed paper. If all printing is too far to the left (or right), adjust what you tell the software about the left and right margins; or if you're using pin-feed paper in a dot-matrix printer with movable tractors, slide the tractors to the left or right (after loosening them by flipping their levers). For example, if the printing is an inch too far to the right, slide the tractors an inch toward the right. INSUFFICIENT MEMORY Here's the newest nuisance ever invented! Problem When you try to install or run a new program (such as a game), the computer says ``Insufficient memory'', even though you bought several megabytes of RAM. Cause Either the program requires even more megabytes of RAM than you bought, or too much of your RAM is being consumed by other purposes. Cure First, find out how much RAM the program requires. If you're lucky, the ``Insufficient memory'' message will include a comment about how much RAM you need. For further details about how much RAM you need, read the program's ``System Requirements'' notice, which appears on the side or back of the box that the program came in. For even more details about how much RAM you need, read the beginning of the program's instruction manual: just before it explains how to install the program, it explains the detailed ``System Requirements''. Notice not just how much RAM the program requires but also what kind of RAM. How much conventional RAM does it require? How much extended (XMS) RAM? How much expanded (EMM) RAM? To find out how much RAM is in your computer at the moment, give the ``mem'' command, like this: C:\>mem That command tells you how much conventional, extended, and expanded RAM you have, and how much of each type is still available. That command works just in DOS 4, 5, 6, and beyond. If you're stuck with an older DOS, say ``chkdsk'' instead of ``mem''. Unfortunately, ``chkdsk'' says just how much conventional RAM you have; it doesn't say how much extended or expanded RAM you have. In most computers, the total amount of conventional RAM is 640K (where a K is 1024 bytes). If you typed CONFIG.SYS and AUTOEXEC.BAT as I recommended on pages 118-123, about 619K of that conventional RAM will be free. If much less than 619K of your computer's conventional RAM is free, increase the conventional RAM by making your CONFIG.SYS and AUTOEXEC.BAT files resemble mine. Here are the fundamental techniques my CONFIG.SYS and AUTOEXEC.BAT files use, to increase the amount of conventional RAM: In CONFIG.SYS, usually say ``devicehigh='' instead of ``device=''. In AUTOEXEC.BAT, usually say ``Lh c:'' instead of ``c:''. In AUTOEXEC.BAT, delete any line mentioning SMARTDRV.EXE. In CONFIG.SYS, say ``buffers=40''. In CONFIG.SYS, say ``dos=high,umb''. In CONFIG.SYS, mention HIMEM.SYS and EMM386.EXE. In CONFIG.SYS and AUTOEXEC.BAT, delete any lines you don't need. The amount of expanded RAM is 0, unless your CONFIG.SYS file contains a line mentioning ``emm386.exe'', and that line has the word ``ram'' in it (instead of ``noems''). To use extended RAM, your CONFIG.SYS file must contain a line mentioning ``himem.sys''. You'll have more extended RAM available if you delete any line mentioning SMARTDRV.EXE and make sure your ``emm386'' line says ``noems'' instead of ``ram''. If you're still short of RAM, buy more RAM chips! To run modern Windows software well, get at least 8 megabytes of RAM altogether.