Symmetricom 5071A, Сборка и сервисное обслуживание

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2. Service
Assembly/Module Diagnostic Trees (Diagnostic Section 3)
96
3.3.1.1. A8 1 MHz Waveform Voltage/Frequency Test
1 Replace the A8 module with a new (or known functional) A8.
2 Repeat procedure 3.3.1, steps 1, 2, and 3 .
QUESTION: Were the correct waveforms observed?
If Yes: A8 is defective, retain new A8 and retest.
If No: Go to, 3.3.1.2, (Another assembly may be loading down the
A8 1 MHz output.)
3.3.1.2. A8 1 MHz Output Signal Loading Test
1 Repeat procedure 3.3.1 after sequentially replacing A2, A3, A4, and A7 one
at a time. (Remove power when changing assemblies.)
QUESTION: Did one or more replaced assemblies correct the
problem?
If Yes: Retain the replaced assembly and retest.
If No: A1 may be defective, contact Symmetricom for further assistance.
3.3.2. Clock Increment Test
1 Set the Instrument LCD display to the
CLOCK/Set
Menu.
2 Verify that the time (hh:mm:ss) display increments at one-second intervals.
QUESTION: Does the time display increment correctly?
If Yes: Go to, 3.3.3.
If No: Go to, 3.3.2.1.
3.3.2.1 Clock Does Not Increment
1 Remove instrument power and replace A8.
2 Reapply power and observe display for time increment.
QUESTION: Does the time display increment correctly?
If Yes: Retain new A8 and retest.
If No: Go to, 3.3.2.2.