Personal Computer Safety (1.1)
What Is in a Computer? (1.1.1)
A computer is an electronic machine that performs calculations based on a set of instructions. The first computers were huge, room-sized machines that took teams of people to build, manage, and maintain. The computer systems of today are both exponentially faster and only a fraction of the size of those original computers.
A computer system consists of hardware and software components. Hardware is the physical equipment. It includes the case, keyboard, monitor, cables, storage drives, speakers, and printers. Software includes the operating system and programs. The operating system manages computer operations such as identifying, accessing, and processing information. Programs or applications perform different functions. Programs vary widely, depending on the type of information that is accessed or generated. For example, instructions for balancing a personal budget are different from instructions for simulating a virtual reality world on the Internet.
Electrical and ESD Safety (1.1.2)
Safety is an important topic and practice in the workplace. Safety guidelines help protect individuals from accidents and injury. They also help protect equipment from damage.
Electrical Safety (1.1.2.1)
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 products connect to ground via the power plug. Large equipment such as server racks house network devices that must also be grounded.
ESD (1.1.2.2)
Electrostatic discharge (ESD) can occur when there is a buildup of an electric charge (static electricity) on a surface that 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 3000 volts (V) 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 10,000V. By comparison, less than 30V 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.