Agilent Technologies 8935 Series, Manual

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50 Chapter 3
Troubleshooting
Self-Test Diagnostics (Step 1)
Self-Test Diagnostics (Step 1)
On power-up the Test Set runs a self-test diagnostic test. Most of the
Test Set’s digital functions are tested. The outcome of the test appears
on the display (if operating) and on four LEDs viewable through an
access hole on the top internal cover.
The self-test diagnostic can be run three ways:
1. The test runs automatically when the Test Set is turned on. After
the Test Set powers up, a message appears at the top of the display.
If one or more tests fail, the message reports the failure with a
hexadecimal code.
During the test, coded failure information is displayed on four LEDs
on the top of the Controller (A2A31) assembly, see
Figure 3-5 on page
53 . The Test Set’s cover must be removed to view these LEDs. See
chapter 3 for disassembly and replacement instructions.
2. The test runs when the Test Set receives the query
*TST?
over GPIB.
The resultant decimal code can be read over the bus.
3. The test runs when the
Self Test menu item of the Functional
Diagnostics menu
is selected.