Agilent Technologies E8285A Manual page 62

Troubleshooting
Functional Diagnostics
Functional Diagnostics Menu
To run the Functional Diagnostics, see
58.
NOTE The diagnostics are intended to help in locating the source of catastrophic failures.
Occasionally, a test will fail with the test results being only slightly out of limits.
Such failures do not necessarily indicate that the Test Set is operating outside of its
published specifications or that it is otherwise faulty. Further testing (such as
running the performance tests) will be required in such cases.
Many of the internal diagnostic and calibration procedures use low-level latch
NOTE
commands to control the instrument settings. Many latch settings persist even
through a preset. They can only be reset by an instrument power down or by
explicitly reseting each latch. This phenomenon is the reason the message
" Direct latch write occurred. Cycle power when done
servicing ." is displayed the first time a latch is written to. Because latch
settings persist, problems can arise in running these programs. For example,
prematurely terminating a test in a diagnostic (using the Pause and Exit keys) and
restarting another test may cause failures in that test because of improper latch
settings. It is best to run tests to completion before starting another one. Also, be
sure to cycle the power off and on when done servicing the Test Set.
Figure 2-14 Functional Diagnostics Screen
Functional Diagnostics
62
S:\agilent\e8285\ALR\Book\chapters\trouble.fm
"Accessing the Diagnostic Tests" on page