A++ 2.3

Be aware of the following additional tips for maintaining your computer

▪When receiving a new computer or components that have been shipped, Let it sit for at least 6 hours (24 hours if it arrives during freezing condition) before applying power, the rapid change in temperature can damage the components or can result in condensation within the computer. ▪Perform regular backups, backups protect your data if the hard drive fails. ▪You can use covers and cases to protect some equipment such as printers from dust and liquid spills. Be sure to remove covers before use and replace after use. ▪Keep cables organized, route cables to prevent them from being kinked or stepped on. For best results use cable ties to bind and organize cables. ▪Verify that your system's cooling fans are blowing air through the system case in the correct direction. A fan blowing in the wrong direction can negate the airflow through the case and cause the system to overheat.

cat 6 cable

a UTP cable type that provides more than 1 GB of throughput

Standby power supply

A standby power supply is an offline device that switches over to provide power when and undervoltage occurs, if the switch over is not fast enough to computer loses power.

Here are some types of interference that affect your computer networks.

Electro magnetic interference EMI and radio frequency interference RFI.

What are the most important things you can do to keep computer systems running is to create a proper environment such as

Heating ventilation and air conditioning, Interference, magnetic fields.

Uninterrupted power supply

Is a online device that is constantly providing power to the computer and being recharged by the wall outlet.

What is interference?

It is a signal that corrupts or destroys regular signals. Interference effects signals used by 2 devices to communicate on a network.

The following is a description of devices used to prevent power problems

Search protectors, line conditioners, stand-by power supply (SPS) and uninterrupted power supply (UPS).

the following devices and components needed for computer repair and maintenance

a combination ratchet/ screwdriver. IC insertion and extraction tool(used to add or remove integrated circuit chips that are used on motherboards). antistatic pad/wrist strap(prevents static electricity from moving between objects and damaging computer components). extension magnet. three pronged parts retriever. multimeter(a device for testing various electrical properties). power supply tester(essentially a custom multimedia). cable tester(verifies that a network can carry a signal from one end to the other, and that all wires within the connector are in their correct position). loopback plug(used to test network communication by redirecting a signal from the transmit port on a device to the receive port on the same device). known good spares. post card(is an expansion board that you insert into an expansion slot, typically used to troubleshoot a computer system that doesn't start up correctly).

sag

undervoltage that lasts milliseconds.

brownout

undervoltage that lasts seconds but dings the lights.

blackout

complete power failure

Line conditioner

modifies the power signal to remove noise and create a smooth alternating current (AC) signal.

surge

overvoltage condition like a spike but with longer duration - seconds

spike

overvoltage condition of short duration and intensity - milliseconds

There are 2 types of UPS systems.

▪ An online UPS constantly powers the computer from the battery. ▪ An offline UPS powers the computer from the wall power. When the power fails a switch inside that UPS switches to power the computer from the battery. This is the most common form of UPS. ▪ A UPS is designed to provide enough power to shut the system down safely during an extended power outage. Most are not intended as long term power solutions ▪ The UPS connects to the power source usually by a wall socket, the computer plugs into the UPS and the UPS is connected through a serial or USB port to the computer. Software on the computer uses this connection to monitor battery life and to detect when the regular power is lost. You can configure the software to shut the system down automatically when the battery charger reaches a certain level. You usually need to configure the following settings when working with UPS software. 1. Time to wait before sending a warning to clients. 2. Time to wait before beginning a shut down 3. Name of programs or commands to run during shutdown ▪ In addition to providing power when the power is lost, most UPS systems also condition the line and remove power spikes and sags. ▪ Most UPS devices sound an alarm when the AC power is lost. This alarm continues until AC power is restored, although many UPS devices have a switch to mute the alarm. ▪ During certain conditions, such as electrical storms or when the power supply is constantly going up or down, you might need to unplug the computer to protect it. Simply turning it off might still damage the components because some power remains supplied to the system, in the case of an electrical storm, keep the system plugged in leaves it susceptible to power spikes.

Magnetic fields located close to a computer can cause undesired effects or even data loss such as

▪ Hard drive and tape storage devices use magnet charges on disk or tape for storing data. while hard disks are shielded and protected for all but the strongest magnets, be careful with tapes. Getting a magnet to 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

Is surge protector protects against over-voltages using these

▪A power strip provides multiple power outlets for a single plug in but is not necessarily a search protector. ▪Surge protectors can be destroyed by surges and lose their ability to protect. ▪Consider using a surge protector with an indicator light to show that it is working correctly.

One of the best things you can do to keep your system running efficiently is to keep it clean. Be aware of the following facts about clean your computer

▪Common computer cleaning supplies include a lint free cloth, compressed air or air compressor, small anti-static vacuum and denatured or I isopropyl alcohol. ▪Regular, periodic cleaning gives you a chance to inspect all components look for a worn or felt components or electrical components dark areas might indicate a burned out component. ▪Prior to cleaning computer components power down and unplug components and let them sit for at least 30 minutes to cool. ▪ Use caution with liquid based cleaners. use small amounts and always apply cleaning solutions to cloth and cleaning instruments, never directly to the component surface ▪ Dust build-up inside a computer acts as an insulator for internal components, trapping heat and preventing adequate cooling. of components to clean user compressed air or a non-ststic vacuum or a natural paint brush. ▪ Use a small amount of denatured alcohol on a cotton swab to clean electrical connections such as those on expansion cards. ▪ For LCD screens, use a little lint free dry cloth or a small amount of Isopropyl alcohol. (do not use window cleaner or ammonium based cleaners or paper towel). You can also use special monitor cleaning solutions are pre packaged wipes with monitor safe solution. ▪ 4 mouse with a Roller Ball, clean the ball in the roller contacts on a regular basis. ▪ For keyboard, use a vacuum or compressed air. for keys that stick use a little lint free cloth or cleaning swabs lightly dampen to gently wipe each key. ▪ To clean a printer, use a damp or dry cloth. On inkjet printers, use the printers cleaning function to clean the print heads. for laser printers, use an anti-static vacuum to remove excess toner. ▪ on removeable media devices use A DDS - approved cleaning tape, to automatically clean the heads of the tape driver. use compressed air to blow dust and debris off the CD-Rom and DVD disk surfaces, out of the driver bays and off the driver heads. use a soft lint free cloth, dry, to wipe smudges off of CD and DVD's disks media services.

EMI is interference that affects wired network 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 cable to eliminate the effect of interference.

For computer components design HVAC Systems with the

▪Keep temperatures between 70 and 74ﾟ to prevent components from overheating. ▪Keep humidity between 40 and 70% to prevent electrostatic discharge (ESD). ▪Make sure server rooms have separate ducking 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 efficient. ▪ For areas with heavy smoke or dust, add filters to air intake systems to filter out airborne particles.

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 used the 2.4 GHz frequency range (801. 11b and 802. 11g) are susceptible to RFI ▪ RFI can be reduced by using a wireless networking standard that operates in the 5.75 GHz range or by using a different channel for wireless devices.