Chapter 5

To avoid EMI

Do not run any cables close to each other if possible Use shorter cables Use shielded cables if EMI is a problem

Why clean your computer?

Less prone to overheating Dust and hair clogs up vents Dirt that settles on chips insulate them, keeping the heat in

Battery Conservation

Carry an extra battery for notebook computer if possible Adjust power settings in the OS to extend the battery life Turn off your wireless network adapter unless you are actively using it Set the screen display to be less bright Set the screen saver to blank the screen after a certain amount of idle time Mute the sound Minimize the use of external devices that draw power from the notebook Remove any unused ExpressCards or other peripheral cards

Electrostatic Discharge (ESD)

Commonly known as static electricity Most common reason for ruined PC parts Occurs when two items of unequal voltage potential touch When current builds up in your body and you touch a part, that current zaps the part ESD is low-current, high-voltage Electronic equipment is extremely sensitive to damage by high voltage You can destroy or weaken a circuit board with ESD without knowing it Any exposed circuit boards are targets for ESD damage Motherboard Expansion boards Memory

Electromagnetic Interference (EMI)

Electricity passing nearby generates a magnetic field that interferes with the operation of a cable or device Also called crosstalk Occurs only when the devices are on and sending data via cable Usually causes no permanent damage, but can cause data loss Can come from: Unshielded cables High-voltage power lines Fluorescent lights Radio transmitters Can cause problems with data corruption, such as a printer printing garbage characters interspersed with normal characters

Grounding to a strap

Grounding can eliminate ESD risk To ground yourself, wear an antistatic wrist strap as you work Attach the other end to a grounding pin in an electrical outlet If no grounding source is available, attach the clip to the PC's metal frame

Making a Backup Plan

How often do you plan to back up? How large are the files? What backup software is available? What files should be backed up: Full: Backs up everything Differential: Backs up what's changed since the last FULL backup Incremental: Backs up what's changed since the last backup of ANY type

Magnets

Magnets can create an electrical charge in a component Physical harm due to overvoltage Electromagnetic interference when operating Use only non-magnetic screwdrivers and other tools inside a PC

Surge Suppressor

Metal oxide variable resistor (varistor) absorbs any excess power Varistor works by depleting its own ability to resist Over time, a surge suppressor loses its effectiveness

Antistatic Plastic bags

New boards come in antistatic plastic bags Keep parts in the bags until you are ready to install them Protection is only in the bag, not on top of it Antistatic spray can minimize static buildup in your work environment Spray on carpet and clothing

Power Conditioning

Power conditioning corrects power sags by boosting the voltage when it is insufficient Power conditioning is often combined with the functions of an uninterruptible power supply (UPS)

UPS

Power conditioning corrects power sags by boosting the voltage when it is insufficient Power conditioning is often combined with the functions of an uninterruptible power supply (UPS)

Surge Suppression and Power Conditioning

Power surge: too much voltage Power spike: an extreme power surge Power sag: too little voltage, also called a brownout

Backup Solutions

RAID systems Local backup applications Online backup services Network backup Manual file copying System imaging

Cleaning Supplies

Spray cleaner May have antistatic properties if designed for computers Spray on a cloth, then wipe; do not spray directly onto computer Monitor cleaner Spray or towelette Specifically designed for monitors (antistatic, no ammonia Can of compressed air Blows dust out of crevices Can be used to cool a hot chip when troubleshooting Cotton swabs and alcohol Not rubbing alcohol (too much water) Antistatic spray Spray on floor in work area to minimize static electricity (Optional) Small hand-held vacuum cleaner designed for electronics Regular vacuums don't have a fine enough filter Regular vacuums generate static electricity when they operate

Ways to Avoid ESD

Synthetic clothing generates more ESD than natural fibers like cotton or wool Avoid working in stocking feet—wear rubber-soled shoes Keep the humidity in the workroom between 50 and 80 percent Work on a tile or linoleum floor, not on carpet

Online UPS

runs off the battery all the time More expensive Slightly more reliable because no quick change-over to battery power is required

Standby UPS

runs off the battery only when regular power is off or insufficient Less expensive If changeover doesn't happen fast enough, devices may lose power momentarily and reboot