Keysight N5224B, Руководство по обслуживанию

Страница: 123 / 614

Keysight N5224B/25B Service Guide 4-39
Troubleshooting
Measurement System Troubleshooting
— for LO related problems, continue testing at “Checking the A15 13.5
GHz LO Synthesizer Output” .
— for source related problems, continue testing at “Checking the A4
and A17 Source Synthesizer Outputs” on page 4-45 .
Checking the A15 Direct Digital Synthesizer (DDS) Assembly Outputs
1
The instrument must be sufficiently reassembled, so it can be safely powered
up.
1. Power up the instrument.
2. Note any error messages in the bottom right hand corner of the PNA’s
display (e.g., "
A power on self test error has occurred.
Please contact...
"). Refer to Figure 4-10 on page 40.
3. A log file is generated by PNA after every power up. To access this log file,
on the PNA, navigate to E:/log/PowerOnTest (Verify that hidden files is
selected). A failure indication similar to "
FAIL: Slug S/N not found
",
indicates the DDS assembly is faulty, for an example of this error in a log
file, refer to Figure 4-11 on page 41.
4. If an DDS failure (e.g., "
FAIL: Slug...
") is observed:
a. Power down the instrument.
b. Verify that the A15 DDS assembly is seated properly.
c. Verify that all cable connections to the A15 DDS assembly are
connected properly.
d. Repeat steps 1 through 3.
e. If the instrument still has a similar “Slug” failure then the DDS is
faulty and needs to be replaced.
5. If the A15 DDS assembly is faulty, contact Keysight Technologies for help.
Refer to “Contacting Keysight” on page 2-7.
1. Th e A15 direct digital synthesizer assembly only applies to PNAs with serial number
prefixes
≥
6021 or
that has been
upgraded with a version 7 synthesizer assembly.