System Troubleshooting - Motorola R-2002A Manual

Communications system analyzer
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5-144.
Spectrum Analyzer
1.
Set the UUT for the Monitor Function of 300 MHz the Spectrum Analyzer Display, and 0 dB input
attenuation. Set at 300 MHz. Connect the Signal Generator to the RF In/Out Jack on the UUT. Verify a
spectral amplitude of -30 dBm ±5 dB on the CRT display. Increase the RF Step Attenuator in 10 dB
increments verifying that the spectral amplitude decreases by 10 dB ±3 dB with each step.
2.
Verify the operation of the Dispersion Control.
5-145.
Duplex Generator
1.
Select the Duplex Generator Display and the monitor Function at a frequency of 100 MHz. Enable the
45 MHz offset frequency. For an Image Low switch position verify that a displayed duplex frequency of
55 MHz can be obtained. Set the Image Switch to the HIGH position and verify a duplex frequency
display of 145 MHz.
2.
Enable the 0- 10 MHz offset frequency and verify that displayed duplex frequencies from 100 MHz to
110 MHz can be obtained.
3.
Set the UUT to the Generate Function with the Duplex Generator Display. With the Code Synthesizer
and the External Modulation sources OFF, adjust the 1 kHz Level Control for a 20kHz FM deviation
reading on the CRT. Select the Monitor Function and adjust the offset frequency for a duplex output of
100 MHz. Connect the Duplex Output Jack to the RF In/Out Jack and verify a 20kHz ±1 kHz FM
deviation reading on the CRT.
5·146.
System Troubleshooting
5-147.
A troubleshooting procedure is outlined in Table 5-6. Because of the complexity of the system the
table covers only the major failures and provides only a guide to the most probable failed module. When using
the table it is important to use the checkout procedure at paragraph 5-126 to determine the fault. The
troubleshooting table assumes that all tests prior to the failure point have been successfully completed and
thus the applicable circuits are okay.
5-148.
A list of the system test points and their functions are provided in Table 5-7. Test points are identified
on the block diagrams for the Theory of Operation discussion of paragraph 5-16 and for the Module
Descriptions to aid in troubleshooting.
Table 5-6.
System Troubleshooting
Test Paragraph
Fault
Troubleshooting Procedure
5-132
No AC indication
1. Check AC linecord and line fuse.
2. If system powers up normally when on,
Replace AC LED.
5-132
No Oven Ready indication
1. Check for approximately +15 VDC at E13 of
the A 13 module. If not present replace the
Low Voltage Power Supply (A 1).
2. Check E11 of A 13 for +9 VDC and E12 for ap-
proximately +7.5 VDC. If E11 is okay and E12
is 0 VDC, replace the LED. If the +9 VDC is not
p resent on E11 re laceA13.
p
5-37

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