HP 8924E, Сборка

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Chapter 2, Troubleshooting
More About Step 1- Run the Power-Up Diagnostic
N:\mkt\MANUALS\HP8924C\ALR\trouble.fb
RF Diagnostics (RFDIAGS3)
This program tests the RF functions of the following assemblies:
• A19 Receiver 1st Mixer
• A26 Output
• A24 Signal Generator Synthesizer
• A27 Reference
• A30 Receiver
• A28 Receiver Synthesizer
• A32 Spectrum Analyzer
• A5 Input
Some tests require cabling before the RF Diagnostics can be run; but all tests can
be run in a loop mode without further intervention. Running in loop mode makes
it easier to catch intermittent failures.
NOTE: The measurement limits of the Functional Diagnostic tests are valid only at room temperature;
that is, 20 to 25
°
C or 65 to 75
°
F.
When a test fails, a diagnosis is given in two parts:
• The name of the assembly or assemblies most likely to have failed.
• A rating (high, medium, or low) of the confidence of the diagnosis.
The diagnosis given by the RF Diagnostics should be verified by other means
before ordering and replacing parts. This particularly applies to the Spectrum
Analyzer, Receiver, and Receiver Mixer assemblies. Some suggestions for doing
this are as follows:
• Become familiar with the block diagram and theory of operation of the assemblies in
chapter 11, "Block Diagrams" .
• Read the description of the diagnostic test in chapter 14, "Diagnostics Descriptions" .
• Follow the suggestions in "Further Isolating RF Failures" on page 96 later in this
chapter.