
          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 8 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.