2.5/2.5.2 PC Maintenance
When should you use to clean a printer?
Damp or dry cloth
Electromagnetic interference (EMI)
Interference that affects wired network signals.
What causes EMI?
EMI is caused by motors, heavy machinery, and fluorescent lights.
Heating, ventilation, and air conditioning (HVAC)
The system installed within buildings to control temperature by supplying heat and air conditioning.
What wireless network frequency range is best used to reduce RFI?
5.75Ghz
Interference
A signal that corrupts or destroys regular signals. Interference affects signals used by two devices to communicate on a network.
Which materials can you use to clean internal PC components?
Compressed air to blow off. A non-static vacuum to remove dust. A natural bristle paintbrush to wipe components off.
Why is dust a hazard to a computer?
Dust buildup inside a computer acts as an insulator for internal components, trapping heat and preventing adequate cooling of components.
Three things to remember about Magnetic fields
Hard drives use magnetic chargers to store data Speakers, motors, and generators contain magnets so keep sensitive components away from these devices Solid-state storage devices (such as ram or flash drives) are not affected by magnetic fields
What is the difference between a positive pressure system and a negative pressure system?
Positive pressure systems protect the air quality forcing air out Positive pressure systems are more energy effective. Negative pressure systems draw air in, potentially bringing in airborne particles
What should you do before cleaning computer components?
Power down unplug components let them sit for at least 30 minutes to cool
How can you eliminate the effects of interference from EMI on signals sent on ethernet twisted pair cabling?
Use fiber optic cables
How can you protect signals sent on Ethernet pair cabling from EMI?
Use shielded twisted pair cables
What should you use to clean laser printers?
anti-static vacuum to remove excess toner
What nearby devices using the same channel can cause RFI?
cordless phones, microwave ovens and wireless devices that interfere with wireless networking.
Radio frequency interference (RFI)
interference on the radio channel used by wireless networking devices.
What should you use to clean an inkjet printer?
printer's cleaning function to clean the print heads
What do you use to clean electrical connectors? (eg. those on expansion cards).
small amount of denatured alcohol on a cotton swab
