PC Hardware ServicingChapter 2: Safety and Preventive

Maintenance

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

Hazard

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

situation.

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.

The top ten hazards for PCs:2. ColdJust 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.

The top ten hazards for PCs:3. HeatProcessors 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.

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.

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).

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.

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.

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.

The top ten hazards for PCs:9. Faulty manufactureThere 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”

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.

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

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

Safety and Anti-Static Rules1. 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.

Safety and Anti-Static Rules4. 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

Safety Hazards when working in the PC

• Do not disassemble a power supply

• Replace entire power supply if defective

1. Remove faulty device or PC parts

• Do not disassemble monitor

• Replace entire monitor if defective

• Have monitor serviced by specially trained technician

2. Use proper Fire Extinguisher

2. Use proper Fire Extinguisher

Steps to protect yourself from hazards

1. Watch out for protruding wires

3. Don’t weardangling jewelry

4. Shirt sleeves canget caught on sharp

edges

Steps to protect yourself from hazards

5. Inner edgesof cases

may be sharp

2. Avoid jewelry ofconductive metals

Anti-Static Wrist Strap

Clips to ground plug or

metal frame of PC case

Wraps around your wrist

Equalize the Potential

• Touch metal frame of PC before touching circuit board or chip

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

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

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

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

Cleaning Methods of PC

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

Cleaning a Monitor

• Do not use regular glass cleaner

• Use glass cleaner designed for monitors

• Do not spray while monitor is turned on

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

Cleaning a Mouse

1. Remove panel on the bottom

2. Remove the ball3. Clean inside with

alcohol and cotton swab

4. Clean ball with soap and water

Cleaning Circuit Boards

• Use paint brush clean edges• Use alcohol if liquid is necessary

Cleaning an Inkjet Printer• Clean the outside with a cloth dampened

with cleaner for PCs• Run the printers self-cleaning utility clean

print head

Disposal of Hazardous Materials

• Make use of your local hazardous waste disposal facility– Cleaning chemicals– Toner cartridges– Monitors– Circuit boards– Batteries

QUIZAnswer 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)

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