From BrycesWiki
Jump to: navigation, search

The following are notes taken from CompTIA A+ Certification Study Guide Seventh Edition by Jane Holcombe and Charles Holcombe, which covers the CompTIA A+ 2009 objectives.

Details

  • provide each computer and all peripherals with a well-ventilated location
  • take time to perform preventive maintenance on PCs for which one is responsible
  • includes
    • regular visual and aural inspection
    • driver and firmware updates
    • component cleaning

Visual and Audio Inspection

  • frequent visual inspections will allow problems with cables and connections
    • true of any computer
  • consciously look at a computer for connection and environmental problems
    • things change
      • pile of papers on top of a powered USB hub
        • causing it to heat up
      • computer or peripheral moved
        • stretched cable or power cable to point of nearly coming out of the sockets
  • aural inspection involves listening for a noisy fan or hard drive
    • may be sign of a pending problem
      • correct before fan or hard drive is lost
        • clean and/or replace fan
        • immediately backup a hard drive that makes unusual noise and take steps to replace it

Drivers and Firmware Updates

  • keep current on driver and firmware updates
  • when moving from an old computer to one with new OS, or upgrade the OS on an existing computer, obtain new device drivers from manufacturers
  • install all critical OS and security updates
  • may need to update firmware, when upgrading OS
    • flash BIOS of system and device

Ensuring a Proper Environment

  • extreme temperature, humidity, and dust particle amounts are damaging to PCs and peripherals
  • best operating environment for a PC is climate-controlled room with a filtration system to control enemies of electronics
  • if PC must work in extreme environments, consider spending money on a case that will provide better ventilation and filtration
  • to find actual temperature and humidity extremes listed in user's or technical manual for PC or component, look under Operating Environment
    • recommended operating environment is in range of 50-90°F and relative humidity between 50 and 80%
      • if not comfortable, neither is PC

Providing Good Power

  • when considering a proper environment for computer equipment, think of the power it receives
  • never plug critical equipment into wall outlet without some provision to protect it from vagaries of power grid
  • while sags in power below the 115 V US standard can cause computer to reboot or power off, a surge can do siginficant damage, and a simple power strip offers no protection because it is nothing more than an extension cord with several power outlets

Surge Protector

  • use surge protector to protect all computer equipment, including
    • modems
    • phone
    • cable lines
    • surge protector may look like ordinary power strip, but protects equipment from power fluctations above the 115 V US standard
  • eventually fails, if first line of defense
    • plug PC into surge protector that has a protection rating of 800 joules
    • look for surge protector that carries the Underwriters Laboratories label showing that it complies with UL standard 1449
      • least expensive power protection device

Beyond Surge Protectors

  • do not just buy minimum, if possible
    • buy the best power protection that can be afforded
    • which should include protection from
      • power fluctuations
      • brownouts
      • voltage sags
      • outages
  • most common device that protects from power outages and reductions is a UPS
    • more expensive than surge protectors, but have come down in price, since manufacturers have introduced consumer-level versions
  • When selecting UPS, determine required watts for each device that will connect to it and time needed to save data when main power fails
  • computer or device plugged into UPS is truly isolated from power source, because it runs off battery through an inverter, rather than switch to battery only after power loss
  • UPS is more expensive than surge protector, but excellent in power protection
  • once lone power to UPS is off, computer runs on limited battery power
  • limit varies by capacity of battery in UPS and how much power the computer draws
    • unless power comes back quickly, use has a window of just a few minutes to save data and power down
  • some UPSes include a data cable and software
    • when installed and UPS senses outage, software will warn to shut down
      • if no one is at keyboard to respond, it will automatically, before UPS itself runs out of battery power:
        • save open data files
        • shut down OS
        • power down computer
  • in real disaster, power can be off for days or weeks, especially for mission critical systems in certain industries, like banking and hospitals
    • expect to encounter backup power generator that can kick in and provide power
      • usually powered by propane or diesel

Maintenance and Cleaning of Computer Components

  • components will last longer and function better with some basic and regular maintenance and cleaning
  • regularly cleaning the fans in power supply and case can ensure they properly cool the computer's internal components
    • preventing system slowdown and potential damage to components

Internal Components

  • one of most common reasoons to clean the insides of a computer is to remove dust buildup to protect system from overheating
  • outside air comes in through ports and is distributed over the internal components, bringing dust with it
    • dust can cause or lead to
      • ESD
      • overheated components
  • pay attention to system board, bottom of computer chasis, and fan inlets and outlets on both the power supply fan and case fans
  • power down computer before beginning to clean it
  • one of the easiest ways to remove dust from system is to use compressed air to blow the dust out
    • comes in cans roughly the size of spray-paint canes
      • typically, liquid Freon in can compresses the air and forces it out, when can's nozzle is depressed
    • tilting or turning can upside down can cause freon release
      • avoid this, since liquid Freon can cause freeze burns on skin and damage computer's components
  • make sure dust is blown from one components does not settle on another
  • can also use compressed air to blow out dust from
    • keyboards
    • expansion slots
    • ports
  • use only canned compressed air, not high-presurre air from a compressor
  • another common method for remaining dust from inside a computer is to use an antistatic vacuum cleaner
    • one that has a conductive path to ground to protect against ESD damage to computer during use
    • advantage of removing dust without allowing dust to settle elsewhere
  • best to use a handheld vacuum to reach smaller places and clean without hitting and damaging other internal components
  • take nozzle out of computer, and move vacuum cleaner away before turning it off

External Components

  • can use lint-free cloth to wipe off dusty surfaces, such as
    • displays
    • keyboards
    • printers
    • PC case exterior
  • antistatic display cleaner is a type of product that contains a gentle cleaning fluid that, when used with a soft cloth, can remove dust and dirt from display screen
  • avoid using newer dust cloths that work by statically attracting dust
    • static is harmful to computer
  • use lint-free cloth to remove dust from display screen
  • use antistatic display cleaner to remove grime
    • spray small amount on cloth, then wipe dirt from display screen
  • for dirt that can't be dusted off, use disposable moistened cleaning wipes on optical discs and most plastic, metal, and glass exterior surfaces, such as display screens
  • liquid cleaning compound, such as isopropyl alcohol, can come in handy for cleaning gummy residue from surface of PC case or a peripheral
  • manufacturer's instructions may also suggest using it for cleaning internal components or other device
    • only do per manufacturer's instructions

Input Devices

  • for devices, such as keyboards, mice, and track ball devices, schedule frequent cleaning
  • for keyboards
    • vacuum crevices between keys
    • turn keyboard upside down over wastebasket and shaking it
    • removes large amount of dust and debris
      • depending on environment and user habits
  • may need to protect keyboard in dirty environment, like an auto repair shop, with special membrane cover that allows use of keyboard, but keeps out
    • dirt
    • grease
    • solvents
    • other harmful debris
  • membrane covers can be found on Internet or in computer supply catalogs under keyboard protectors category
  • for rarely used devices, consider using dust covers that remain on device until needed
  • to clean an optical mouse
    • turn it over
    • locate the tiny lens
    • wipe it with a soft static-free cloth
  • to clean track ball, simply remove the ball and wipe socket with a soft static-free cloth
  • to clean rollers on traditional mouse
    • unplug mouse and turn it upside down
    • remove retaining ring
    • invert mouse so the ball drops into hand
    • if ball is sticky or dirty, clean it with warm, soapy water and rinse it thoroughly
    • locate rollers inside mouse
      • typically two long black rollers and one small, metallic roller
    • use fingers to remove ring of dust from each roller
      • take care that no material falls further into mouse
    • if rollers are sticky, or previous step is insufficient, use cotton swab dipped in isopropyl alcohol to clean them
    • when finished, replace mouse ball and retaining ring, ensuring they are securely in place
    • plug mouse back in
      • if USB, computer can remain running
    • with computer running, test mouse

Storage Devices

  • common storage devices also require regular maintenance for better performance

Hard Drives

  • maintenance includes
    • running a utility called Defrag or disk optimizer
      • to reorganize fragmented files on disk
    • CHDSK or ScanDisk
      • to discover disk problems
  • run on regular basis
    • perhaps once a week on drive in which files are saved and deleted often

Optical Media and Drives

  • prevent damage by keeping discs clean
  • commercial optical disc cleaning and repair kits are readily available to restore optical discs
  • can simply wipe any type of optical disc clean with antistatic cloth
  • for more stubborn dirt, use plain water or isopropyl alcohol on cloth
  • ensure disc is dry before inserting into drive
  • BD have hard-coating - beyond that found on older types of optical discs - that resists scratches
  • if disc is too badly scratched, may need to replace it
    • if irreplaceable or too expensive to replace, and there is nothing to lose, consider polishing disc
  • never clean an optical drive that works properly, but if necessary, use compressed air to blow out dirt from drive
  • if drive has lens in disc tray, it will be visible when tray extends
    • carefully clean with an antistatic cloth dampened with isopropyl alcohol
      • too much alcohol can damage drive
  • be wary of kits for cleaning optical drives, because some use a small brush or felt pad to clean the lens of drive
    • unintended consequences, such as scratching the lens
    • if used, follow directions carefully as improper use can cause more problems than it solves

Floppy Drive Maintenance

  • cleaning kits can be purchased at many computer retail or parts stores
    • typically includes
      • cleaning solution
      • something similar to regular floppy disk
  • in most cases, apply solution to disk and insert it into drive
    • drive cleans read/write heads as they try to access the disk

Thermally Sensitive Devices

  • many components within PC are thermally sensitive
    • should only operate within recommended operating environment
  • transporting PC or other thermally sensitive device requires being aware of environment
    • if in cold climate and bring new PC home when it is 20°F below 0, be sure to let PC sit and acclimate before plugging it in and turning on
      • if PC feels cold to touch when unpacking, acclimate time should be extended to several hours
        • as it warms up, some condensation will occur on internal components, and PC needs time to dry out
  • thermally sensitive devices include
    • motherboards
    • CPUs
    • adapter cards
    • memory
    • printers