4-12 Keysight N5224A/25A Service Guide
Troubleshooting
Power Up Troubleshooting
4-
1.
Unplug the A23 test set motherboard ribbon cable from the A23 test set
“Removing and Replacing the A23 Test Set
2.
Unplug the A23 test set motherboard to A24 IF multiplexer board ribbon
cable from the A24 IF multiplexer board (refer to
the A24 IF Multiplexer Board” on page 7-30
3.
Unplug the front panel interface cable from the A1 front panel interface
board (refer to
“Removing and Replacing the A1–A3 and Other Front Panel
).
4.
Remove the A16 SPAM board (refer to
“Removing and Replacing the A4–
5.
Remove the A10 source board (refer to
“Removing and Replacing the A4–
6.
Remove the A5 source board, if present (refer to
the A4–A17 Boards” on page 7-14
).
7.
Remove the A15 13.5 GHz synthesizer board (refer to
Replacing the A4–A17 Boards” on page 7-14
).
8.
Remove the A17 13.5 GHz synthesizer board (refer to
Replacing the A4–A17 Boards” on page 7-14
).
9.
Remove the A4 13.5 GHz synthesizer board, if present (refer to
and Replacing the A4–A17 Boards” on page 7-14
)
10.
Remove the A14 frequency reference board (refer to
Replacing the A4–A17 Boards” on page 7-14
).
11.
Remove the A22 GPIB board (refer to
“Removing and Replacing the A22
). Reinstall the A20 power supply assembly and
the A21 CPU board assembly.
12.
Unplug the A55 solid state drive from the A21 CPU board (refer to
“Removing and Replacing the A55 Solid State Drive (SSD)” on page 7-49
).
The minimum required assemblies to power up the analyzer are:
— A20 power supply
— A19 midplane board
— A18 system motherboard
— A21 CPU board
To further isolate the failure in the three remaining assemblies, measure the
resistance (with the power turned off) from the power supply test points to
either ACOM or DCOM.
Make sure that the only assemblies plugged in are the four minimum
required assemblies listed above.