1. Preventive Maintenance
Preventing System Failure

2. System Failure
failure that occurs because of a hardware failure or a severe software issue. Commonly, a system failure will cause the system to freeze, reboot, and/or stop functioning altogether.
Is the prolonged malfunction of a computer. It may result from loss of hardware, software, data, or information.

3. System Failure May result from a variety of causes: Aging hardware
Natural disasters
Random events such as electrical power variation

4. What is PM
Preventive maintenance is a schedule of planned maintenance actions aimed at the prevention of breakdowns and System failures..

5. Preventive Maintenance Program
The main goal of any preventive maintenance program is to pre-empt problems before they happen.
There are three questions that need to be addressed when developing a preventive maintenance program. This means asking when, why, and how?
When is the best time to prevent problems from happening?
Why is this maintenance being done now?
How is this system to be maintained?

6. Long-term benefits of preventive maintenance include:
Improved system reliability.
Decreased cost of replacement.
Decreased system downtime.
Better spares inventory management.
Long-term effects and cost comparisons usually favor preventive maintenance over performing maintenance actions only when the system fails.

7. Tools and Equipment
A technician should have a toolbox that contains the basic tools as shown in the graphic.
A toolkit should also include the following:
Flat-head screwdriver
Phillips-head screwdriver
Nut drivers
Needle-nose pliers
Diagonals or crosscut pliers
Mirror to help see in tight places
Digital multimeter
Flashlight

8. Tools and Equipment
The toolset should also include a digital multimeter (DMM).
A DMM can perform electrical tests and measure voltage, amps, and ohms in both alternating and direct current.
A DMM can be used to test power supplies, DC/AC voltage and polarity, resistance, diodes, continuity, coaxial cable, fuses, and batteries.

9. Electrostatic Discharge (ESD)
Static electricity is the buildup of an electric charge resting on a surface.
ESD is the worst enemy of the fine electronics found in computer systems.
At least 3000 volts must be built up before a person can feel an ESD. If the discharge causes pain or makes a noise, then the charge was probably above 10,000 volts.
Most computer chips run on less than five volts of electricity.
A computer component could be damaged by less than 3000 volts of static buildup.

10. Electrostatic Discharge (ESD)
Special packing materials are used with microchips and Printed Circuit Boards (PCBs).
Do not remove any component from special packaging until it is ready to be installed.

11. Electrostatic Discharge (ESD)
When working on a computer or the individual components, some tools should be used to reduce the risk of ESD.
A grounding wrist strap provides a place for the static to go before it attacks a sensitive computer component.
Note: A wrist strap should not be worn when working with high-voltage equipment, such as a power supply or a CRT monitor.

12. Wrist Strap

13. Cleaning Peripheral Devices
When cleaning a display (monitor), make sure the device is unplugged from the wall.
Use a damp cloth with a mild detergent to wipe down the entire display unit and remove any dust buildup.
Dampen another cloth with water to remove any cleaner residue on the surface of the monitor.
After cleaning the display, use a dry cloth to complete the job.

14. Cleaning Peripheral Devices
A mechanical mouse may not function properly if it becomes dirty.
When dust settles on the mouse pad, it gets swept up into the moving parts of the mouse.
This causes a buildup on the rollers inside the mouse.
The fastest way to clean it is to remove the plate on the bottom of the mouse, remove the ball, and then gently scrape the dust buildup from the rollers.

15. Cleaning Peripheral Devices
Keyboards are also exposed to the environment, which allows dust to build up on the keyboard over time.
Periodic cleaning of the keyboard will prolong the lifespan and prevent malfunction.
The keys on a keyboard can be removed to allows easy access to the areas where dust collects.
A soft brush or cotton swab can be used to remove dirt from under the keys.
Compressed air can be used to blow out dust from below the keys.

16. Cleaning Peripheral Devices
Printers have many moving parts within them.
They require a higher level of maintenance.
Printers also produce impurities that collect on the components within the device.
Over time, these impurities need to be cleaned out.
Otherwise, they may cause the printer to malfunction.

17. Utilities
There are several utilities included with DOS and Windows that help maintain system integrity.
If used on a regular basis, the following utilities can increase system speed and efficiency.
ScanDisk – This utility is used to check the integrity of files and folders or to thoroughly check the system by scanning the disk for physical errors.
Defrag – This utility optimizes space on the hard drive to allow programs to execute faster.
CHKDSK /f – This command is used to check the file system for errors and can be compared to the ScanDisk for Windows 2000 and XP.
REGEDIT – provides access to the Registry in a view similar to Windows Explorer.

18. User Responsibilities
There are a few things that the end user of a computer can do in order to make the system work properly.
Using the system utilities are one way of making a system run smoother.
Managing applications
Managing files and folders
Backing up the work

19. Firewalls
Security breaches on a home computer may allow a hacker to steal stored data or use the computer to hack into other computers.
A home firewall can be used to prevent hacker attacks on a home computer.
A firewall is a hardware or software system that is used to prevent unauthorized people from accessing sensitive data.

20. Firewalls
A typical home firewall system also includes the following features:
Closes the broadband connection after detecting any attempts to hack into a digital appliance
Allows different family members to set their own levels of security
Records all broadband Internet access events
All data, video, and voice traffic between these two networks is examined by the firewall.

21. Firewalls
After installing a firewall, certain ports will need to be opened to use and the Internet.
SMTP uses port 25 and POP uses port 110 to transmit and receive .
Port 80 will also need to be opened for HTTP, the standard protocol that supports the exchange of information on the World Wide Web.

22. Firewalls
Windows XP has a built in firewall called Internet Connection Firewall (ICF)
ICF is a software component that blocks unsolicited traffic from the Internet.
ICF monitors all the outbound and inbound communications of a computer.
If ICF does not recognize a packet being sent or received, the packet is dropped.

23. Power Issues
Computers components are vulnerable to various kinds electrical fluctuations and can be damaged by electrical discharges because of the delicate nature of the internal components.
Blackouts, brownouts, noise, spikes, and surges are all examples of power interruptions that can cause system malfunctions or even complete system failure.

24. Power Issues
Computers components are vulnerable to various kinds electrical fluctuations and can be damaged by electrical discharges because of the delicate nature of the internal components.
Blackouts, brownouts, noise, spikes, and surges are all examples of power interruptions that can cause system malfunctions or even complete system failure.

25. Power Issues
Blackouts – Blackouts are the complete loss of power for any amount of time
Brownouts/Sags – Sags and brownouts are a drop in power
A sag is a brownout that lasts less than a second.
Brownouts occur when voltage on the power line falls below 80 percent of the normal voltage.
Noise – Noise is caused by interference from radio broadcasts, generators, and lighting.

26. Power Issues
Spikes – Spikes are sudden increases in voltage that are much higher than normal levels. If the event lasts one or two seconds, it is called a spike. These are usually caused by lightning strikes.
Power Surge – Is a dramatic increase in voltage above the normal flow of electrical current.

27. SURGE PROTECTOR
All computers have some surge protection built in, but this protection is not always enough. External surge protectors come in the form of a unit that plugs into the wall, with outlets for several electrical plugs. However, not all outlet bars have surge protection.

28. Surge Suppressors Uninterruptible Power Supplies
Surge suppressors, also known as surge protectors can help guard against electrical surges and spikes.
A surge suppressor works by diverting the extra voltage to the ground.
A surge suppressor is useless during brownouts or blackouts.
Uninterruptible Power Supplies
A UPS runs off the battery power the entire time it is in use.
A UPS can help guard against power sags or brownouts.

29. UNINTERRUPTIBLE POWER SUPPLY / UPS
A UPS is not necessary on most computer systems, but can be important on systems that need to be up 24 hours a day, such as servers.

30. Surge Suppressors
Uninterruptible Power Supply

31. ANY QUESTIONS?
Please read Chapters
See you next class!!!