Keysight Technologies N5221A, Руководство по обслуживанию

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Keysight N5221A/22A Service Guide 4-35
Troubleshooting
Measurement System Troubleshooting
Too many sections! Equipment Setup
1. Before starting these checks, zero and calibrate the power meter. (See the power
meter user’s guide for instructions on setting the calibration factor.)
2. If the
Receiver Display
(
Figure 4-7
or
Figure 4-8
) is not on the analyzer screen,
perform the following: Press UTILITY , then , then ,
then .
3. Set the sweep speed for a 10 second sweep: Press STIMULUS , then
. Set the time to 10.000 seconds in the
Sweep Time
box.
To isolate a broadband RF signal generation failure, check the test port output power:
1. Note the power reading displayed on the power meter; it should be the preset
power level +/- 1 dB.
2. Connect the power sensor, in turn, to Ports 2, 3, and 4 and set trace to measure
S22, S33, and S44 respectively. Note the power reading displayed on the power
meter.
— If the power level is low or high on all test ports, the problem is LO signal related.
Continue with
“Checking the A10 50 MHz Reference Outputs”
.
— If the power level is low or high on only one of the test ports, the problem is either
source group or in the signal separation group. Continue with
“Checking the A10
50 MHz Reference Outputs”
to check the source group.
Checking the A10 50 MHz Reference Outputs
1. Refer to the block diagram at the end of this chapter and to “Top Cables,
All Cables—All Options” on page 6-19 . Locate flexible cables W65, W66,
and W67, at the A10 frequency reference board.
2. Disconnect cables W65, W66, and W67, one at a time, from the A10
board.
3. Connect the spectrum analyzer to the open connector on the A10 board.
4. The spectrum analyzer should measure a signal at 50 MHz.
5. If any of the 50 MHz signals are not present, replace the A10 frequency
reference board. Refer to “Removing and Replacing the A4–A13 Boards”
on page 7-15 .
6. If the 50 MHz signals are present, reconnect the cables, and then:
— for LO related problems, continue testing at “Checking the A11 13.5
GHz LO Synthesizer Output” .
— for source related problems, continue testing at “Checking the A4
and A13 Source Synthesizer Outputs” on page 4-37 .
System
Service Utilities
Receiver Display
Sweep
Sweep Time