Agilent Technologies 856290216 Test Connectors, Inconsistent Results, Erroneous Results

Test Connectors

The TAM uses a built-in dc voltmeter and DAC to measure voltages on any one of the “test connectors” (or test jacks) located throughout the spectrum analyzer.

Revision Connectors

One test connector on each assembly is reserved as a “revision connector.” The TAM uses the revision connector to identify the assembly design revision. A “revision voltage” placed onto one measured signal line (MSL) pin, indicates design changes.

The TAM must be plugged into the revision connector first to determine which tests to use for the assembly. If the revision connector has not been probed, a message will appear instructing you to connect the probe to the revision connector and press TEST. You can then probe the rest of the assembly connectors.

Note	If the revision of the PC board is newer than the TAM, a message will be
	displayed stating that the revision code for this board is not known by this
	module. The choices presented are to use the test for the latest known
	revision board, measure only voltages, or exit. In general, most points will not
	change from one board revision to another, so using the most current tests
	is still very useful. However, any failure should be verified using the manual
	troubleshooting procedures before doing a repair.

Inconsistent Results

Many of the signals measured by the TAM are digitally controlled. If inconsistent results are obtained, or if failures appear in unrelated areas, the digital control may be at fault. Refer to the manual troubleshooting procedures for those assemblies to isolate those failures.

Erroneous Results

If the TAM manual probe troubleshooting seems to be giving erroneous results, its performance can be checked by placing the probe on the TAM test connector (A2Jll) located on the A2 controller assembly and executing the manual probe diagnostics. If either of the tests fail, the TAM is malfunctioning and should be serviced.

Blank Display

It is possible to use the TAM manual probe troubleshooting without a display if an HP-IB printer is available. Refer to Chapter 13, “Display/Power Supply Section,” for more information.

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General Troubleshooting 7-13