Module 12 Preventive Maintenance and Upgrading 12.1 – Preventive Maintenance and the Technician 12.2 – Preventive Maintenance and Electrostatic Discharge (ESD) 12.3 – Preventive Maintenance for Computer Peripherals 12.4 – Preventive Maintenance for Computer Software
Preventive Maintenance and the Technician
Elements of a Preventive Maintenance Program The main goal of any preventive maintenance program is to preempt problems before they happen. There are three questions that need to be addressed when developing a preventive maintenance program: 1.When is the best time to prevent problems from happening? 2.Why is this maintenance being done now? 3.How is this system to be maintained?
Tools and Equipment Every technician toolbox should contain the basic tools. A wide variety of flat-head and Phillips-head screwdrivers should be carried in a technician toolset. Diagonals or crosscut pliers allow the technician to precisely cut wires and cabling to their specifications. A good toolset should include a socket set.
Tools and Equipment The toolset should include a meter, which is a measuring device. A digital multimeter (DMM) combines the functionality of a voltmeter, ohmmeter, and an ammeter into one easy to use device.
Tools and Equipment Loop-back plugs can provide important diagnostic information while troubleshooting serial and parallel ports. It works by sending signals out and verifying if the correct input is received back. Diagnostic information can be gained from individual pins, ports, controllers, and printer output.
Environmental Guidelines What to do with the old computers or parts? Can they simply be placed in the garbage bin so that they are hauled to the landfill and buried? Computers and peripherals contain some environmentally unfriendly materials. Most computer components are either hazardous or contain some level of hazardous substances. Waste materials are listed as hazardous because they are known to be harmful to human health and the environment when not managed properly.
Environmental Guidelines for a Server Room Never put the server against ductwork or next to the air conditioner. Be aware of items that can cause interference with electrical pull and EMI, utilize only isolated grounding circuits. A typical server would operate in the following ranges: –Operating temperature: 50º F to 95º F –Storage temperature: –40º F to 105º F –10,000 BTU/hour max heat dissipation
Environmental Guidelines for a Server Room Too much humidity in the air and the moisture can damage the server electronic components. Too dry and the environment can be subject to electrostatic discharge (ESD). If the air quality is questionable, clean out the system using a computer vacuum cleaner or some canned air. Carbon dioxide extinguishes a fire by reducing the oxygen content of the protected area below the point where it can support combustion. If you are unable to save the equipment before a flood, the equipment will be damaged or completely unrecoverable. To keep them from affecting the server, monitor the temperature, line voltage, and other environmental operating statistics of the server.
Proper Disposal of Hazardous Materials Batteries often contain rare earth metals that can be harmful to the environment. Because of these metals, depleted batteries are classified as hazardous materials. The disposal of batteries is tightly controlled both at the national and state or local levels. The desired method for the proper disposal of batteries is recycling, if possible.
Proper Disposal of Hazardous Materials Monitors must be disposed of in compliance with environmental regulations. Laser printer toner cartridges can be refilled and recycled. Ink cartridges from ink-jet printers can also be refilled and reused. Solvents and other liquid cleaning materials must be properly categorized and disposed of at an appropriate type of disposal center.
Using Material Safety and Data Sheets (MSDS) A Material Safety and Data Sheet (MSDS) is a fact sheet that summarizes information about material identification. This includes hazardous ingredients that can affect a person health, fire hazards involved in using the material, and first aid requirements.
Preventive Maintenance and Electrostatic Discharge (ESD)
Electrostatic Discharge (ESD) Overview Static electricity is the buildup of an electric charge resting on a surface. For a person to feel an ESD, there must be at least 3000 volts built up. If the discharge causes pain or makes a noise, then the charge was most likely above 10,000 volts. Most computer chips run on less than 5 volts of electricity.
Anti-Static Bags When purchasing components to assemble a computer, special packing materials are used with microchips and Printed Circuit Boards (PCBs). These packing materials range from special molded plastics and foams for microchips to anti- static bags for PCBs. Do not remove any component from special packaging until it is ready to be installed.
Grounding Wrist Straps A grounding wrist strap provides a place for the static to go before it attacks a sensitive computer component.
Compressed Air Compressed air or anti- static spray as solutions can be used on floors, desks, and in some cases on the equipment itself.
Grounded Workbench There is no need for a grounding mat when computers and other electronic devices requiring grounding are placed on a grounded surface during repairs. A few key elements to a good working area should be anti-static tile on the floors, grounded workbenches with anti-static mats, and wrist straps. The area should be clean, well lit, and the humidity level should be maintained between 20% to 50%. If all of these elements are in place, the risk of ESD will be significantly reduced.
Preventive Maintenance for Computer Peripherals
Monitor Since the display unit attached to the computer is the most visible piece of equipment, it is a good idea to keep it clean for both looks and functionality. Make sure the device is unplugged from the wall. Using a damp cloth with a mild detergent, wipe down the entire display unit to remove any dust buildup.
Mice There are two different types of mice, mechanical, and optical. A mechanical mouse can act jumpy if it gets dirty. 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. An optical mouse may need a damp cloth on the optical sensor surface. Be sure to unplug the optical mouse when cleaning.
Keyboard A keyboard, takes the most abuse of any of the components that make up a computer system. They are also open 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.
Cleaning Printers When working with dot matrix printers, clean the roller surfaces with a damp cloth. There are two things to remember when cleaning a laser printer. 1.To clean a toner mess, use the right vacuum cleaner. 2.Unplug the unit before cleaning it due to the high amounts of voltage within the laser printer.
Scanners If dust or any foreign items make the glass dirty, consult the user guide for manufacturer cleaning recommendations. Try using glass cleaner and a soft cloth so the glass does not get scratched.
Computer Software PM
Software Utilities There are several utilities that are included with DOS and Windows that help maintain system integrity. Scandisk is used either to check the integrity of files and folders or to do a more thorough check of the system by scanning the disk for physical errors. Defrag was created to optimize space on the hard drive so that programs execute faster.
Software Utilities CHKDSK /f– This command is used to check the file system for errors and can be compared to the scandisk for Windows 2000/XP. REGEDIT– The registry is a database that holds configuration data about the hardware and environment of the PC.
User Responsibilities These are ways to manage files and programs to improve performance: –Manage applications –Manage files and folders –Back up the work
Anti-Virus To prevent a virus from infecting the system, the best defense is an anti-virus application. Viruses are typically sent as attachments. Once opened, the virus will infect the computer and send itself out using addresses found in programs like Microsoft Outlook. This is a list of the most common forms of viruses: –File Virus –Boot Sector Virus –Macro Virus
Firewall Reducing the risk of security attacks on your system is accomplished with a Firewall. Windows XP includes Internet Connection Firewall (ICF), that is accessed in network connection properties box. 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.
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 are the complete loss of power for any amount of time. Brownouts/Sags are a drop in power.
Power Issues Noise is caused by interference from radio broadcasts, generators, and lightning. Spikes are sudden increases in voltage that are much higher than normal levels. Power Surge is a dramatic increase in voltage above the normal flow of electrical current.
Surge Suppressor and Power Supplies Surge suppressors guard against electrical surges and spikes. It works by diverting the extra voltage to the ground. A standby power supply (SPS) is equipped with a backup battery to supply power when the incoming voltage drops below the normal level. The battery is on standby during the normal operation of the unit.
Surge Suppressor and Power Supplies An uninterruptible power supply (UPS) is comparable to SPS. However, a UPS runs off the battery power the entire time it is in use. The power coming into the unit recharges the batteries while they are in use. It is a device that protects against AC power issues and provides a limited supply of power in the event of a power failure.
UPS in a Server Environment The UPS may be free standing next to the server or rack mounted. It is plugged directly into the power source. The server and its components are then plugged into the UPS. A serial or USB cable that runs from the UPS to a port on the server gives the network operating system the capability to monitor the UPS.
UPS in a Server Environment After installing the UPS monitoring software, the following parameters have to be to configured: –Time to wait before sending a warning to clients that the server is running on battery power. This is generally a few seconds. –Time to wait before beginning a shutdown of the network server. This is generally a few minutes. –Name of a program or group of commands to run as part of the shutdown process.
UPS in a Server Environment Upgrading an UPS could mean replacing the UPS battery or putting a UPS with a larger VA rating in place of a smaller UPS. A UPS upgrade might be required for any of the following reasons: –The current UPS does not provide power for a time period that is long enough to allow the network server to shut down gracefully –The network server power requirements have increased because of the addition of power-consuming hardware to the network server –The amount of equipment that must be supported by the UPS during a power failure has increased