1.1 Personal Computers
1.1.1 What is in a Computer?
220.127.116.11 Video Explanation - What’s in a Computer?
Click Play in the figure to see an explanation of what is in a computer.
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1.1.2 Electrical and ESD Safety
18.104.22.168 Electrical Safety
Follow electrical safety guidelines to prevent electrical fires, injuries, and fatalities.
Some printer parts, such as power supplies, contain high voltage. Check the printer manual for the location of high-voltage components. Some components retain a high voltage even after the printer is turned off.
Electrical devices have certain power requirements. For example, AC adapters are manufactured for specific laptops. Exchanging AC adapters with a different type of laptop or device may cause damage to both the AC adapter and the laptop.
Electric equipment must be grounded. If a fault causes metal parts of the equipment to become live with electrical current, the ground will provide a path of least resistance for the current to flow harmlessly away. Typically computer product connect to ground via the power plug. Large equipment such as server racks that house network devices must also be grounded.
Electrostatic discharge (ESD) can occur when there is a buildup of an electric charge (static electricity) that exists on a surface which comes into contact with another, differently charged surface. ESD can cause damage to computer equipment if not discharged properly. Follow proper handling guidelines, be aware of environmental issues, and use equipment that stabilizes power to prevent equipment damage and data loss.
At least 3,000 volts of static electricity must build up before a person can feel ESD. For example, static electricity can build up on you as you walk across a carpeted floor. When you touch another person, you both receive a shock. If the discharge causes pain or makes a noise, the charge was probably above 10,000 volts. By comparison, less than 30 volts of static electricity can damage a computer component. Static buildup can be discharged by touching a grounded object prior to touching any electronic equipment. This is known as self-grounding.
ESD can cause permanent damage to electrical components. Follow these recommendations to help prevent ESD damage:
Keep all components in antistatic bags until you are ready to install them.
Use grounded mats on workbenches.
Use grounded floor mats in work areas.
Use antistatic wrist straps when working inside computers.