CompTIA A+ 220-1001 - PC Maintenance

Surge suppressor

A device that protects systems from damage from a power surge by suppressing the over-voltage.

Surge protector

A device that protects systems from over-voltages by switching the system off.

Uninterruptible power supply (UPS)

A device that provides battery power to a computer in case of an under-voltage or power failure.

Which of the following statements about cleaning monitors and display devices is true?

A monitor should be powered off and cleaned with a lint-free cloth.

_______ is a signal that corrupts or destroys regular signals; affects signals used by two devices to communicate on a network

Interference

Spike

An over-voltage that lasts milliseconds.

Removable media

On removable media devices, use: * Compressed air to blow dust and debris off of CD-ROM and DVD disc surfaces, out of drive bays, and off of drive heads. * Soft, dry lint-free cloths to wipe smudges off of CD-ROM and DVD disc media surfaces.

Which of the following features should you look for when selecting a vacuum cleaner for your cleaning kit?

One that blows as well as vacuums Non-static generating

Line conditioner

A device that modifies power signals to remove noise and create a smooth AC electrical signal.

Electromagnetic interference (EMI)

A signal caused by motors, heavy machinery, and fluorescent lights that interferes with wired networking signals.

Standby power supply (SPS)

An offline devices that provides power when an under-voltage occurs.

Surge

An over-voltage that lasts seconds.

Sag

An under-voltage that lasts milliseconds.

Brownout

An under-voltage that lasts seconds.

Your company provides testing services that help customers identify and resolve performance issues with their software and e-commerce sites before they go live. To perform accurate testing, a large number of computers are required, sometimes numbering in the hundreds. Recently, you have noticed that the lights in the testing lab seem dimmer than normal and sometimes flicker. Which of the following electrical terms BEST describes the condition you are most likely experiencing?

Brownout

Blackout

Complete power failure.

Which of the following are common tools used to physically clean the inside of a computer?

Compressed air Natural bristle brush

Dust

Dust buildup inside a computer acts as an insulator for internal components, trapping heat and preventing adequate cooling of components. Use: * Compressed air to blow dust off. * A non-static vacuum to remove dust. * A natural bristle paintbrush to wipe components off.

Electromagnetic Interference (EMI)

EMI is interference that affects wired networking signals. * EMI is caused by motors, heavy machinery, and fluorescent lights. * Use shielded twisted pair cable to protect signals sent on Ethernet twisted pair cabling. If necessary, use fiber optic cables to eliminate the effects of interference.

LCD Screens

For LCD screens, use a lint-free dry cloth or a small amount of isopropyl alcohol (do not use window cleaner, ammonium-based cleaners, paper towels). You can also use special monitor-cleaning solutions or pre-packaged wipes with monitor-safe solution.

Mouse Ball

For a mouse with a roller ball, clean the ball and the roller contacts on a regular basis.

Heating, Ventilation, and Air Conditioning (HVAC)

For computer components, design HVAC systems with the following in mind: * Keep temperature between 70 and 74 degrees to prevent components from overheating. * Keep humidity between 40 and 70 percent to prevent electrostatic discharge (ESD). * Make sure server rooms have separate ducting or HVAC systems from the rest of the building for better temperature control. * Use positive pressure systems. Positive pressure systems protect the air quality in the facility by causing air to be forced out through doors, windows, and other openings. Negative pressure systems draw air in, potentially bringing in airborne particles such as dust or smoke. Positive pressure systems are more energy effective. * In areas with heavy smoke or dust, add filters to air intake systems to filter out airborne particulates.

Keyboards

For keyboards, use a vacuum or compressed air. For keys that stick, use a lint-free cloth and/or cleaning swabs, lightly dampened, to gently wipe each key.

Which of the following device types should be plugged into a surge-protected-only outlet on a UPS unit, and not a battery backup outlet?

Laser printer

A new laptop was delivered to your home and left on the porch while you were at work. It is very cold outside, and you don't know how long it has been there. You unpack the computer. You would like to know if it is working properly. Which of the following is the BEST action to take?

Let the computer warm up to room temperature before turning it on.

Common computer cleaning supplies include

Lint-free cloth Compressed air or an air compressor Small anti-static vacuum Denatured or isopropyl alcohol

Magnetic Fields

Magnetic fields located close to a computer can cause undesired effects or even data loss. * Hard drives use magnetic charges to store data. While hard disks are shielded and protected from all but the strongest magnets, getting a magnet too close to these components could erase data. * Speakers, motors, and generators contain magnets (keep sensitive components away from these devices). * Solid state storage devices (such as RAM or flash drives) are not affected by magnetic fields.

Power during cleaning

Prior to cleaning computer components, power down and unplug components and let them sit for at least 30 minutes to cool.

Besides protecting a computer from under-voltages, a typical UPS also performs which other actions?

Protects from over-voltages Conditions the power signal

Radio Frequency Interference (RFI)

RFI is interference on the radio channel used by wireless networking devices. * RFI can be caused by nearby wireless devices using the same channel, cordless phones, or microwave ovens. * Wireless networks that use the 2.4 GHz frequency range (801.11b and 802.11g) are susceptible to RFI. * You can reduce RFI by using a wireless networking standard that operates in the 5.75 GHz range or using a different channel for wireless devices.

Radio frequency interference (RFI)

Signals caused by cordless phones, microwave ovens, and wireless devices that interfere with wireless networking.

Which of the following devices help protect equipment from temporary, above-normal voltages?

Surge protector

What does occasional beeping from the UPS mean?

The computer is running on the UPS battery power.

Heating, ventilation, and air conditioning (HVAC)

The system installed within buildings to control temperature by supplying heat and air conditioning.

Printer cleaning

To clean a printer, use a damp or dry cloth. * On inkjet printers, use the printer's cleaning function to clean the print heads. * For laser printers, use an anti-static vacuum to remove excess toner

Your company resides in an area with rapid growth in both the corporate and residential areas surrounding your office. As such, your company has been experiencing several brownouts due to power grid problems (too much demand and not enough electricity). Fearing that your computers (especially the servers) could be damaged by these brownouts, your manager has asked you to find a solution to this problem. Which of the following would be the BEST device to recommend to your manager for computer protection?

UPS

Denatured alcohol

Use a small amount of denatured alcohol on a cotton swab to clean electrical connectors (such as those on expansion cards).

You are trying to help a co-worker order a UPS for each PC in her remote office location. What rating is used to specify the size of a UPS?

Volt-Amp (VA)

Liquid-based cleansers

Use caution with liquid-based cleansers. Use small amounts and always apply cleaning solutions to cloths and cleaning instruments, never directly to component surfaces.

Which of the following is most helpful in keeping a computer cool?

Vacuum dust from the system regularly. Verify that cooling fans are not circulating air in the wrong directions.