26 Computer Service and Repair
operates on magnetic principles should not come
in contact or close proximity to a magnetic field.
In the early days of electronics and computers,
magnets were used to bulk erase data from
data storage devices such as tapes and floppy
disks. Bulk erasers were very powerful magnetic
devices.
The most common source of magnetic field
in computer repair is magnetic tools, such as
screwdrivers with a magnetic tip. In the early days
of computer technology, magnetic tools could
destroy all data stored on a floppy disk. Floppy
disks are seldom encountered today, so views
have changed about the use of magnetic tools and
there has been some debate. Some say the hard
drive can be corrupted by magnetism, but this is
not necessarily true. The case surrounding a hard
drive is metallic and generally acts as a shield to
protect the disks inside from a magnetic field.
Some types of computer chips can be damaged by
strong magnetic force, but most are designed with
some form of magnetic shielding.
There are computer technicians who do use
magnetic tipped tools such as screwdrivers and
have never encountered a problem. However, as a
Goodheart-Willcox Publisher
Figure 1-37. Anti-static bag holding a static-sensitive
device. Be sure to save anti-static bags and use them to
temporarily store electronic components while making
repairs.
general rule, you should never use magnetic tools
inside a computer case.
Radio Frequency Interference (RFI)
Radio frequency interference (RFI) is
interference produced by electronic devices that
use radio waves. In general, radio waves are very
weak and do not damage electronic components,
but they can interfere with radio transmissions
between electronic devices. Wireless network
devices can fail or operate erratically because
of radio frequencies broadcast by other devices.
For example, a wireless network device can be
temporarily affected by a microwave oven while
the oven is running. Some common devices that
generate RFI are baby monitors, cell phones,
cordless phones, wireless network components,
and microwave ovens.
Tool Kit
Computer repair requires a minimum number
of tools, Figure 1-38. A standard tool kit can vary
from a small pouch to a more elaborate tool case.
A variety of flat tip, Phillips, and star drivers
are needed. Canned compressed air, a chip
puller, anti-static wrist strap, multimeter, extra
screws, and a Torx driver set are also helpful
tools. Additionally, some type of extraction tool
for retrieving dropped screws and other parts is
definitely needed.
Goodheart-Willcox Publisher
Figure 1-38. Standard small tool kit. This kit contains the
basics. More elaborate kits are available.