Transcript Module 2
Module 2 PC Technician Safety Measures Personal safety is your top priority when working with computer components. • Exercise great care when working with electricity. • Before handling a system component, make sure that it is powered off and that the main power cord is unplugged from the wall socket. • DO NOT open the power supply which houses a capacitor (stores a large charge of electricity). • Anti-static wrist straps not only protect components, but can reduce the chance of accidental electrical shock. Properly ground yourself before working with components. • Do not use a grounding strap when working with monitors, power supplies, laptop LCD panels, or other high-voltage components. Safety Measures • Maintain and periodically review the Material Safety Data Sheet (MSDS). The MSDS describes safe handling procedures for dangerous materials. Keep in mind the following specific issues that can also be hazardous: • Do NOT service CRT monitors. They can store 30,000 volts of electricity, even when unplugged. Be sure to discharge capacitors or turn the equipment over to qualified personnel for servicing. • Components such as the CPU heat sink and fan, the printing head of a dot matrix printer, or components inside a laser printer can be hot. • Some studies suggest that laser printers emit tiny particles which could be dangerous when inhaled. As a precaution, do not locate laser printers immediately next to desks, and keep the area ventilated. • Replace faulty power supplies instead of trying to repair them. ESD Static electricity is the accumulation of an electric charge (produced by friction) on a non-grounded object. The static charge can jump when it contacts the surface of any grounded object. This electric discharge is known as electrostatic discharge (ESD). ESD can be very destructive to a computer. ESD can cause immediate failure of components, or could gradually degrade components, causing only intermittent problems. ESD Implement the following measures to protect against ESD. • Keep the relative humidity between 40-70% and temperature between 7277 degrees. Avoid dry air in the computer repair location. • Use antistatic mats under the PC and on the floor. • Discharge yourself before touching any computer component. • When touching anything inside the computer, wear an antistatic wrist strap that is attached with an alligator clip to the metal PC chassis. • Ground both yourself and the computer to the same ground. This provides a single path for the flow of electrical potential. • Never touch the metal connectors on a circuit board. • Store sensitive components in static-shielded bags (also called anti-static bags; they are usually tinted gray) • If a wrist strap is unavailable, keep your body in constant contact with the metal frame when working inside the computer. Note: Unplug the system before working on internal components. Do not rely on the power cord for an electrical ground. Environmental Facts Component or Material Disposal Method Alkaline batteries Recycle if possible, otherwise dispose of in the regular trash. Notebook battery packs Considered hazardous waste. Return to manufacturer, recycle, or contact local Button batteries authorities for disposal procedures. Monitor Contact local authorities. CRTs contain many toxic and caustic substances that are illegal to incinerate and must be encased in cement before being buried. Also, discharge before disposal (CRTs can contain high voltages.). Power supply Contact local authorities. Discharge before disposal (contains high voltages). PC system Contact local authorities. Recycle if possible: the typical PC contains $5 to $25 worth of precious metals. Laser printer toner Return to manufacturer for recycling (to clean up spills, use a toner vacuum or a scoop and a damp cloth; never use a regular vacuum). Ink-jet printer cartridges Consult with local authorities for recycling possibilities. Cleaning solutions and Consult the MSDS, a licensed disposal organization, or local authorities for handling solvents and authorized disposal procedures. PC Maintenance Facts Consideration Description Keep temperature between 70 and 74 degrees to prevent components Heating, from overheating. Keep humidity between 40 and 70 percent to ventilation, and air prevent ESD. conditioning For areas with heavy smoke or dust, add filters to air intake systems to (HVAC) filter out airborne particulates. Interference Electromagnetic Interference (EMI) Radio Frequency Interference (RFI) Magnetic fields Magnetic fields located close to a computer can cause undesired effects or even data loss. Getting a magnet too close to these components could erase data. Magnets near a CRT monitor can distort the images on the screen.CRT monitors, 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 Protection Facts Problem Description Surge Over voltage that lasts seconds Spike Over voltage that lasts milliseconds Sag Under voltage that lasts milliseconds Brownout Under voltage that lasts seconds (lights dim) Blackout Complete power failure Troubleshooting Process Facts 1. Identify the problem. Resist the urge to start fixing things at this point. 2. Before making changes to the system, back up user and system data. 3. Identify possible causes and identify a theory of a probable cause. 4. Test your theory to verify the cause of the problem. 5. Create an action plan, addressing the most likely problem. 6. Test the result. 7. Demonstrate the result. 8. Document the solution and process Windows Utilities Facts • • • • • • • • • • • • Control Panel Task Manager Microsoft Management Console (MMC) Computer Management Event Viewer Services Performance Monitor Reliability Monitor System Information (Msinfo32) System Configuration Utility (Msconfig) Command Prompt Regedit