HP Omnibook 500 Troubleshooting and Diagnostics 3-21
Note that the serial and parallel port tests are more thorough if you connect a loop-back connector to
the port before running the test for that port. See the wiring diagrams below.
14
1
25
13
6
1
9
5
Figure 3-3. Serial and Parallel Loopback Connectors
These connections
are not used.
Diodes are 1N4004
or equivalent
(I
F
=1A, V
F
=1V@1A,
V
R
=30-400V)