HP 8924E, Сборка

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Chapter 14, Diagnostics Descriptions
Description Of Audio Diagnostics (AFDIAGS3)
N:\mkt\MANUALS\HP8924C\ALR\diagnos.fb
Description Of Audio Diagnostics (AFDIAGS3)
Introduction
The Audio Diagnostics are divided into seven tests. In each test, a diagnosis of the
failures is made at the end of all the measurements in that test. Even though each
test is independent from the others, it is recommended that all tests be run in the
order presented on the menu screen.
The failure codes are keyed to the circuit names in the block diagrams
accompanying the test explanations. If an explanation is ranked
(high)
, there is a
high probability that the assembly named is faulty. A rank of
(medium)
is shown
when more than one assembly is listed and it is unclear which assembly is most
likely at fault. A rank of
(low)
indicates that the assembly named is not the only
suspect assembly.
Audio circuits not tested by the Audio Diagnostics are:
• A15 Signaling Source/Analyzer - audio analyzer portion
• A34 Modulation Distribution -circuits associated with the MIC/ACC jack, AM and FM
outputs
• A35 Audio Analyzer 1 - some of the inputs
• A36 Audio Analyzer 2 - speaker drive, volume control, ALC
• General - digital control
Audio Frequency Generators 1 and 2
This test checks the ability of Audio Frequency Generators 1 and 2 on the A15
Signaling Source/Analyzer assembly to generate the DC levels programmed into
them.
The Audio Frequency Generators are located on the Signaling/Source Analyzer
assembly.
In this test, a “walking 1” (that is, 0, 1, 2, 4,…, 1024) is input to the DAC. The DC
output level is measured by the Test Set’s internal DVM through a dedicated
multiplexer line. The output level should be proportional to the programmed
input.