IMPORTANT!!!!  Discharging static electricity:  Whenever opening a computer case to work inside, you should discharge the static electricity on your body by holding your fingers against a grounded metal surface anywhere on the edge of the computer case.  Static electricity can damage the sensitive electronic components inside a computer, so precaution should be taken not to shock them.  If you intend to work on a computer for an extended period of time, you may want to consider purchasing an anti-static wrist strap (available at most electronics and computer parts stores), which will keep you grounded and free of static the entire time you work on the PC.

VIDEO - discharging static electricity

IMPORTANT!!!!  Always power the computer off before performing any work inside the case!!!  Avoid damage to system components and danger to yourself by always turning the computer off and unplugging the power cable before performing any service work.

IMPORTANT!!!!  NEVER attempt to open the system power supply or the computer monitor.  These two devices contain concentrated amounts of electricity, which can hurt or kill a person.  When working on a computer, be sure to follow the safety guidelines that apply to working on any electrical appliance.  As a general rule, avoid touching capacitors with your body or any conductive material, even after the computer has been shut off, as capacitors can store large dangerous charges.

Please note:  This set of lessons is intended as a general introduction to the various types of components which make up modern computers.  Each piece of hardware, however, is unique.  Before working with any piece of equipment, you should read and follow all of the descriptions and warnings provided by the manufacturer of your particular hardware.