Unless you follow proper procedures,
working inside your computer can
Cause serious damage to both you and your computer. To assure safety in
Your work
setting, follows every safety precaution.
IMPORTANT SAFETY PRECAUTIONS
In
some of these activities, you remove the cover of a computer and examine the
components. Before you carry out the
exercises in this chapter, carefully read the following precautions focus
specifically on the activities outlined below.
However, there are many risks posed by other maintenance activities, a
number of which you will undertake n the course of working with this book. The Preface presents a comprehensive list of
precautions that should be carefully reviewed as well.
Protect against electricity
You
can actually destroy a computer chip with static electricity when you touch it,
even though you might not feel a thing.
Follow these rules to protect chips while you handle them:
1.
Never touch the inside of a computer while it is turned on.
2.
Never touch any component inside the computer without first
grounding yourself to discharge any static electricity on your body. The best way to do this is to wear a ground
bracelet or ground strap. If you don't
have a ground bracelet, then leave the computer plugged in while you are
working on it so that it will be grounded.
For the PC to be grounded, it must have a three-prong plug and outlet,
but does not need to be turned on.
Touch the metal case or power supply each time before you touch any
component to discharge the electricity on your body.
3.
Don't work on carpet.
Work on a bare floor because a carpet collects static electricity,
especially in cold weather.
4.
Consider both the power supply and monitor to be a
"black box". Don't open
either unless you are trained to understand the dangers and safety precautions
for these devices. The power supply and
the monitor have enough power inside them to kill you.
Other valuable rules
1.
When taking boards from a PC, don't stack them. Stacking them can cause components to become
loose.
2.
Keep screws and spacers in an orderly place, such as a cup
or tray.
3.
Make notes as you work so that later you'll be able to
backtrack.
4.
In a classroom
environment, after you have reassembled everything but putting the comer back
on, have your instructor check your work before
you power up.
EXAMINE THE SYSTEMBOARD
1. Look at the back of your computer. Without opening the case, list the
ports that you believe to be coming directly from the systemboard.
2. Now look inside the case to verify your
list.
a. Follow these directions to remove the
cover:
§
Turn off the PC
§
Unplug and move the
monitor, mouse, and keyboard out of your way.
§
For a desktop case,
locate and remove the screws on the back of the case. Look for the screws in each corner and one on top center. Be careful that you don't unscrew any other
screws besides these. The other screws
probably are holding the power supply in place.
§
After you've removed
the cover screws, slide the comer forward and up to remove it from the case.
§
For tower cases, the
screws are also on the back. Look for
screws in all four corners and down the sides.
Remove the screws and then slide the comer back slightly before lifting
it up to remove it.
b.
Identify the following major components. Drawings in this and previous
chapters should help.
§
Power supply
§
Floppy disk drive
§
Hard drive
§
Systemboard
List the different circuit boards in the
expansion slots. Was your guess correct
about which ports come from the systemboard?
3. To expose the systemboard so you can
identify its parts, remove all the circuit boards following these
procedures. (If you are working with a
tower case you can lay it on its side so the systemboard is on the bottom.)
- To make reassembling easier, take notes
or make a sketch of the current placement of boards and cables. You can mark a cable on a
card with a marker if you like.
Note the orientation of the cable on the card. Each cable for the floppy disk drive,
hard drive, or CD-ROM has a color on one side of the cable called the edge
color. This color marks pin 1 of
the cable. On the board, pin 1 is
marked either as the number 1 or 2 beside the pin or, on the back side of
the board, with a square soldering pad.
- Remove the cables from the
card. There is no need to remove
the other end of the cable from its component (floppy disk drive, hard
drive, or CD-ROM). Lay the cable
over the top of the component or case.
- Remove the screw holding the board
to the case.
- If you aren't wearing a ground
bracelet, touch the case before you touch the board.
- Grasp the board with both hands
and remove the board by rocking the board from end to end (not side to
side). Rocking the board from side
to side might spread the slot opening and weaken the connection.
4. Examine the board connector for the
cable. Can you identify pin 1? Lay the board aside on a flat surface.
5. You probably will be able to see most
if not all the components on the systemboard now without removing anything else. Draw a diagram of the systemboard
and label these parts:
§
The CPU (include the
prominent label on the CPU housing)
§
RAM (probably SIMMs)
§
Cache memory
(probably one or more smaller SIMMs)
§
Expansion slots
(identify the slots as ISA, EISA, MCA, PCI, VLB, ect)
§
Each port coming
directly from the systemboard
§
Power supply
connections
§
ROM BIOS chip (copy
the writing on the top of the chip to paper.
Identify the manufacturer, serial number, and date of manufacture of the
chip.)
6. Draw a rectangle on the diagram to represent each bank
of jumpers on the board.
7. You can do the following activity only
if you gave the documentation or the systemboard: Locate the jumper or jumpers
on the board that erases CMOS and/or the startup password and label it on your
diagram. It is often found near the
battery. Some boards might not have
one.
Mr. DeMerle’s
initials ______________
8. You are now ready to reassemble. Reverse the disassembling activities
above. Place each card in its slot (it
doesn't have to be the same slot, just the same bus) and replace the
screw. Don't place the video card near
the power supply.
9. Replace the cables, being sure to align
the colored edge with pin 1. (In some cases it might work better to connect the
cable to the card before you put the card in the expansion slot.
10. Plug in the keyboard, monitor, and
mouse.
11. In a classroom environment, have the
instructor check your work before you power up. Mr. DeMerle’s initials ______________
12. Turn on the power and check that the PC
is working properly before you replace the cover. Don't touch the inside of the case while the power is on.
13. If all is well, turn off the PC and
replace the cover and its screws. If
the PC does not work, don't panic! Just
go back and check each cable connection and each expansion card. You probably have not solidly seated a card
in the slot. After you have
double-checked, try again.
PRACTICE ACTIVITY
Using old or defective expansion cards and
systemboards, practice inserting and removing expansion cards and chips
PRINT A SUMMARY OF YOUR SYSTEM
HARDWARE
1. In Windows 95, right-click the My Computer icon.
2. On the File menu, select Properties.
3. Click the Device Manager tab.
4. View devices by type.
5. Click the Ports (Com & LPT) icon.
6. Click on the Print button.
7. Print Selected class or device.
UNDERSTANDING HARDWARE DOCUMENTATION
Obtain the manual for the systemboard for
your PC. List at least three functions
of jumpers on the board as well as the corresponding jumper numbers. Scan them
for future use. Mr. DeMerle’s
initials ______________
LEARN TO USE WINDOWS 95 HELP FEATURE
1. In Windows 95, click the Start button on the Taskbar.
2. Click Help.
3. Click the Contents tab.
4. Open Troubleshooting.
5. Select and print If you have a hardware conflict.
RESEARCH THE MARKET
1. In a current computer magazine, find
the speed and price of the fastest PC CPU on the market today.
2. In a current computer magazine, find
the speed and price of the fastest PC RAM module on the market today.
FINAL CHECK LIST OF ITEMS TO TURN IN TO
THE INSTRUCTOR. (2 per group)
|
q
A list
the ports that you believe to be coming directly from the systemboard
and a checkmark next to your correct answers. (item 1 page 2) |
Notes or a sketch
of the current placement of boards and cables. (item 3a page 2) |
|
q
a diagram
of the systemboard and label these parts: |
q
A SUMMARY
OF YOUR SYSTEM HARDWARE (page 5) |
|
q
RESEARCH
THE MARKET (page 6) |
q
|
Extra credit on a 486 only and with
Mr. DeMerle’s approval __________________
SAVING AND RESTORING CMOS SETTINGS
In chapter 2, you used Nuts
& bolts to record CMOS settings to a rescue disk for later recovery. In this chapter, you use the Internet to
download a shareware utility to record CMOS settings and later recover them.
1.
Access the Internet and then go to this address:
www.shareware.com. Search on
"CMOS" to list the various shareware utilities available. Select and download CMOS20.ZIP. You can then exit the Internet.
2.Explode the
compressed file and print the CMOS.TXT documentation file. Three utility programs are included.
§
CMOSSAVE.COM saves the CMOS settings to a file.
§
CMOSCHK.COM compares the CMOS settings to the last
saved version.
§
CMOSREST.COM restores the CMOS settings from the
file.
3. Access a DOS
prompt and save the CMOS settings to a file on a floppy disk using this
command: CMOSSAVE.COM A:\MYFILE.SAV
4.
Compare the settings stored in the file to the
current CMOS settings using this command: CMOSCHK.COM A:\MYFILE.SAV
USING A
SYSTEMBOARD DIAGNOSTIC UTILITY
A well-known diagnostic utility is AMIDiag from American
Megatrends, Inc. The utility is
DOS-based and works under both DOS and Windows 95. You can download the utility from the Internet.
1.
Access the Internet and then go to this address: www.shareware.com.
2.
Locate the Quick Search text box and search on
"amidiag" (don't enter the quotes).
3.
Leave the Internet and explode the file by
double-clicking it in either Windows 3.1 or Windows 95.
4.
Go to a DOS prompt and change to the directory where
the demo software files are stored.
5.
Execute the first program by entering this command:
AMIDIAG
6.
Perform the test of processor speed. What is the detected speed.
7.
Under the Memory menu, perform all the tests that
this demonstration version of the software allows. Record any errors detected.
8.
Under the Misc. menu, perform the serial port
test. Write down any error messages
that you get. If you get an unexpected
error, perform the test more than once.
Do you get the same results each time?
9.
Under the Options menu, ask for System
Information. If you received errors in
the test above, this program might lock up, and you might need to reboot. If you complete the information check
successfully, write down the results.
10.
Under the Systemboard menu, select the option DMA
Controller Test. Why doesn't this test
work?
Exit the program, returning to the DOS prompt.
TROUBLESHOOT
SETUP ERRORS
Change DIP switches, jumper, or CMOS configuration on a
systemboard. (First make sure someone
records the original settings.)
Troubleshoot the system. Use
this opportunity to learn to take notes as you work. List each error you encounter and what you did to work toward a
solution. Mr. DeMerle’s initials
______________
OBSERVING
HARDWARE CONFLICT ERRORS
Have someone set up a troubleshooting practice problem by
forcing two hardware devices on a PC to use the same IRQ. Troubleshoot the problem. Take notes as you go. Describe the errors that you see and what
you are doing to solve the problem.