Lesson

1. PC Hardware Servicing
Chapter 2: Safety and Preventive
Maintenance

2. Chapter 2 Objectives
• Top 10 hazards of the Computer and its
Identification.
• Identify potential safety hazards when
working on PCs
• Identify fire extinguisher types
• Understand electrostatic discharge
• Understand electromagnetic interference
• Be able to properly and safely clean a PC
• Know how to dispose of hazardous materials

3. Hazard
• Danger or risk.
• May result in damage, accidents or unwanted
situation.

4. The top ten hazards for PCs:
1. Knocks/bangs.
Computers are sensitive machines, simply
moving a PC to another room can cause havoc
(destruction), disrupting the delicate circuitry
and hard drives.
Dropping a computer or severe knocks and
bangs will permanently damage the circuits and
processors or dislodge wiring.

5. The top ten hazards for PCs:
2. Cold
Just as with heat, computers don't enjoy
the too much cold either.
Processors will not operate at all if the
operating temperature is too cold as
condensation inside the machine can
freeze and expand damaging the
processor and electronics.

6. The top ten hazards for PCs:
3. Heat
Processors can run exceptionally hot and if
a computers cooling system is inadequate
(because the machine has been upgraded,
overclocked or just clogged up with dust
and grime) it will only be a matter of time
before it packs up for good. It might hang
or slow.

7. The top ten hazards for PCs:
4. Water/fluids
Of course computers are electrical
and with all electrical equipment,
computers and water do not mix, just one
spilt cup of coffee could see the end of
your PC.

8. The top ten hazards for PCs:
5. Dirt/Dust.
A dusty environment will clog a computer and
block cooling vents causing a computer to
overheat. Dust can also contain conductive
material and particles can stick to circuit boards
and cause a short circuit.
A cloud of dust can also explode if it comes into
contact with a source of ignition (like a
computer).

9. The top ten hazards for PCs:
6. Power surge/cut.
Power surges or unexpected power cuts
can not only cause instant loss of data but
can also fry a processor rendering it
useless. It is not just power from the grid
that causes problems either, lightning can
surge through cables (even phone wires)
frazzling your system and a build up of
static can cause similar results.

10. The top ten hazards for PCs:
7. USB Device Mishaps.
It seems everything can be plugged into a
USB these days. However, it maybe that
your USB device is not suited to the
operating system you use or it may be
faulty leading to a fatal short circuit.

11. The top ten hazards for PCs:
8. Bad upgrades.
It is not just computers themselves that are
victims of bad workmanship, upgrades by
inexperienced computer fitters can cause
horrendous problems and faulty add-ons
such as RAM can kill a processor instantly.
Also attempting to 'overclock' a processor
can often lead to a fatal melt-down.

12. The top ten hazards for PCs:
9. Faulty manufacture
There are an almost infinite number of
manufacturers and assemblers, that produce an
increasing number of computer systems are
faulty when bought new.
Mass production leads to low-cost but low
quality of product or “Bad batches of PC”

13. The top ten hazards for PCs:
10. User/Human errors
From not powering down properly to
skipping scan disks, a user can seriously
damage a computer's hardware,
particularly drives and processors by not
following correct guidance in using their
machine.

14. Steps to Control Hazard and Risk
• Eliminating – to remove its completely.
• Substitution – to replace or substitute a
hazardous agent or work process with less
dangerous one.
• Engineering control – Changing a piece of
machinery

15. Steps to Eliminate Hazard and Risk
• Avoid twisting body.
• Bend knees if it is needed.
• Use a ladder when reaching for hard-to-reach
materials or object.
• Ask for help from someone if the task cannot
be done by one person.
• SAFETY FIRST

16. Safety and Anti-Static Rules
1. Always use an anti-static wrist strap when working on
a computer (except when working on monitors)
2. Always disconnect a computer from the AC power
and from any powered peripherals while you are
working on it.
3. Always grasp a metal part of the computer chassis
with your bare hand before you touch anything inside.
Do this even if you are wearing an anti-static
wristband.

17. Safety and Anti-Static Rules
4. Always handle electronic components by a non-
conducting (non-metallic)edge. Don't touch the pins
or other connectors.
5. Never plug an ATX power supply into AC power
unless it is connected either to a computer's
motherboard or to a dummy test load.
6. Always use a approved surge protector or an
Uninterruptible Power Supply(UPS) that incorporates
surge and spike protection.
7.Never eat, drink, or smoke while working on a
computer

18. Safety Hazards when
working in the PC

19. • Do not
disassemble a
power supply
• Replace entire
power supply if
defective
1. Remove faulty device or PC parts

20. • Do not
disassemble
monitor
• Replace entire
monitor if
defective
• Have monitor
serviced by
specially trained
technician

21. 2. Use proper Fire Extinguisher

22. 2. Use proper Fire Extinguisher

23. Steps to protect yourself
from hazards

24. 1. Watch out for
protruding wires
3. Don’t wear
dangling jewelry
4. Shirt sleeves can
get caught on sharp
edges
Steps to protect yourself from hazards
5. Inner edges
of cases
may be sharp
2. Avoid jewelry of
conductive metals

25. Anti-Static Wrist Strap
Clips to
ground
plug or
metal
frame of
PC case
Wraps
around
your wrist

26. Equalize the Potential
• Touch metal frame
of PC before
touching circuit
board or chip

27. Avoiding ESD in Environment
(electrostatic discharge/ESD)
• Work in a room with humidity between 50%
and 80%
• Wear natural fibers, not synthetic
• Wear rubber-soled shoes when possible
• Stand on a ESD-dispersing floor mat if
available

28. Electromagnetic Interference (EMI)
• Manage and organize cables to avoid EMI
• Electricity passing through cable generates a
magnetic field.
• Magnetic field can interfere with data passing
through nearby cables, causing data
corruption

29. Preventing EMI
• Use EMI-shielded cables in areas where it is an
issue
• Use short cables when possible
• Move cables so they don’t run together
• Relocate the PC to a different location

30. Other PC Hazards
• Temperature: PCs prefer cool areas, but keep
above freezing
• Trauma: Don’t place PCs where they can be
kicked or knocked off
• Magnets: Magnets can ruin data stored on a
disk. Magnets may be found in speakers and in
some older phones, as well as magnetic tools

31. Cleaning Methods of PC

32. Cleaning Supplies for a PC
• Spray cleaner designed for external computer
parts
• Vacuum designed for electronics
• Denatured alcohol
• Cotton swabs
• Clean dry lint-free cloths
• Air compressor

33. Cleaning a Monitor
• Do not use regular
glass cleaner
• Use glass cleaner
designed for
monitors
• Do not spray while
monitor is turned
on

34. Cleaning a Keyboard
• Turn off the PC before cleaning keyboard
• Turn keyboard upside-down and shake gently
to remove loose particles
• Get between the cracks with a cotton swab or
a bit of folded paper towel
• Clean keys with a cloth dampened with spray
cleaner designed for PCs

35. Cleaning a Mouse
1. Remove panel on
the bottom
2. Remove the ball
3. Clean inside with
alcohol and cotton
swab
4. Clean ball with
soap and water

36. Cleaning Circuit Boards
• Use paint brush clean edges
• Use alcohol if liquid is necessary

37. Cleaning an Inkjet Printer
• Clean the outside with a cloth dampened
with cleaner for PCs
• Run the printers self-cleaning utility clean
print head

38. Disposal of Hazardous Materials
• Make use of your local hazardous
waste disposal facility
– Cleaning chemicals
– Toner cartridges
– Monitors
– Circuit boards
– Batteries

39. QUIZ
Answer the following(in any order):
1. Give the top ten hazard of PC (10 points)
2. Give the 3 steps to control hazard (3 points)
3. Give the 5 steps to Eliminate Hazard (5 points)
4. Give the 3 Other PC Hazards (3 points)
5. Give 2 of the steps on how to protect yourself
and the PC from hazards and explain why it is
important (4 points)

40. Assignment:
In one half sheet of paper (crosswise).
List down possible steps in
troubleshooting Motherboard.