Hardware Reference
In-Depth Information
Logic probes are especially useful for troubleshooting a dead system. By using the probe,
youcandeterminewhetherthebasicclockcircuitryisoperatingandwhetherothersignals
necessary for system operation are present. In some cases, a probe can help you cross-
check the signals at each pin on an integrated circuit chip. You can compare the signals
present at each pin with the signals a known-good chip of the same type would show—a
comparisonthatishelpfulinisolatingafailedcomponent.Logicprobesalsocanbeuseful
for troubleshooting some disk drive problems by enabling you to test the signals present
on the interface cable or drive-logic board.
Outlet (Receptacle) Testers
Outlet testers (also called
receptacle testers
) are very useful test tools. These simple, in-
expensive devices, sold in hardware stores, test electrical outlets. You simply plug in the
device, and three LEDs light up in various combinations, indicating whether the outlet is
wired correctly (see
Figure 20.8
).
Figure 20.8
A typical outlet/receptacle tester.
