​2-1 Protection and Safety

​2-1
Protection and Safety

• Before handling a system component, make sure that it is powered off and that the main power cord is unplugged from the wall socket.

• Ensure that the grounding pin on a PC power plug is intact.

• Unplug the system before working on internal components. Newer power supplies constantly pull power from the socket.

• Be aware that the power inverter (power supply) converts AC to DC. Also be aware that the power supply can retain an electrical charge, even when it's not plugged in. Replace faulty power supplies instead of trying to repair them.

• Avoid opening the power supply, which houses a capacitor (stores a large charge of electricity).

​​Power hazards can cause electrical shock and burns.

​A capacitor is a device that stores an electric charge. Be sure to discharge capacitors or turn the equipment over to qualified personnel for servicing. Similarly, exercise caution when working with the DC converter in a laptop display.

​Capacitor

ESD is the flow of electricity from one electrically charged object to another. While some ESD can be unnoticeable to the human senses, it can still be hazardous to computer components.
Take the following precautions when handling electronics:

• Use ESD wrist straps not only to protect components, but to reduce the chance of accidental electrical shock. Properly ground yourself before working with components.

• Do not use an ESD wrist strap when working with monitors, power supplies, laptop LCD panels, or other high-voltage components.

• Exercise caution when wearing jewelry, because it readily conducts electricity and could cause burns or even electrocution.

​​Electrostatic discharge (ESD)

• Do not use a regular multimeter or other electrical testing equipment to measure charge inside a monitor.

• Never clean the monitor's glass with a liquid solvent while the monitor is powered on.

• 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.

• Avoid handling leaky batteries. The leaking electrolytes can be harmful if they get into your eyes.

• Never look into the end of a fiber optic networking cable. Laser light can damage your eyes.

​​ Peripherals

A material safety data sheet (MSDS) provides information related to potential hazards and safety precautions within an organization. A MSDS should include:

A listing of hazardous chemicals or components.

Potential effects of exposure.

Requirements for the handling and storage of hazardous materials including such things as:

Proper battery disposal

Proper toner disposal

Proper disposal of other devices and assets

Response plan if accidents do occur.

Plan for responding to injuries.

Plan for securing hazardous materials.

​​Material Safety Data Sheet (MSDS)

​Electrostatic Discharge (ESD)

​Static electricity is the accumulation of a friction-caused electric charge on a non-grounded object. The static charge on the surface of a non-grounded object 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.

The threat of ESD begins when the fragile components (including the processor, hard drives, memory, motherboard, and expansion cards) inside the computer are exposed. You can cause damage simply by placing a fingertip too close to a component inside an open computer case. ESD charges can travel through wires and into components, where the wires can explode or fuse together, causing the components to fail. ESD can cause immediate failure of components or could gradually degrade components, causing only intermittent problems. It takes very little ESD to damage a component. A discharge of as little as 10 volts can damage a component, but 3,000 volts or more of ESD must occur before you can even feel it.

ESD Safety Measures

• Keep the relative humidity in the room at an ideal range of 35-70%, and temperature between 72-77 degrees. The key is to avoid dry air in the computer repair location to prevent ESD.

• 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 to the metal PC chassis with an alligator clip.

• Ground both yourself and the computer to the same ground. This provides a single path for the flow of electrical potential.

• Use static-resistant materials to handle computer components.

• Never touch the metal connectors on a circuit board.

• Keep the computer repair location free of materials that accumulate electric charges, such as plastic and Styrofoam.

• Store sensitive components in static shielding bags, which are usually grey. Static-resistant bags are not nearly as effective. They are usually tinted pink or blue.

• Unplug the system before working on internal components. Do not rely on the power cord for an electrical ground.