Front Panel Active Led; Rf Out Failures; Lo Out Failure - Keysight Technologies N5290/1A PNA Series Service Manual

N5290/91A Troubleshooting
N5292A Test Controller Troubleshooting

Front Panel Active LED

Front Panel power switch LED check. If the power switch LED indicator is not
operating, verify the power switch cable connection on both the front panel
and the test set motherboard (TSMB) is connected securely. Proceed to the
next section for further troubleshooting before replacing the power switch
keypad board. Refer to
Panel Power Switch Board" on page
— Verify the TSMB LEDs are on. Refer to
Motherboard (TSMB)" on page

RF OUT Failures

If the test ports are not switching, or fail the Operational Check the following
procedures can be used to verify the failure. The procedures assume power
supplies, test set motherboard, and front panel LEDs are working. Suspect the
LOPA, LODA, phase compensation board, and ribbon cable connections to the
test set motherboard (TSMB). Refer to
on page
1. Swap millimeter-wave heads.
2. Inspect the ribbon cable connections from the LOPA, LODA, phase
compensation boards to the TSMB. If necessary re-seat the connector(s).
Refer to
4-14 on page
3. Start by measuring the power at A2 LOPA, A3 LODA, or A4 phase
compensation board. If you find incorrect power levels and suspect a
component has failed verify the DC voltages in
and
voltages are OK, then refer to
Phase Compensation Boards" on page
component.

LO Out Failure

If the LO Out fails the Operation Verification test the following procedure can
be used to verify the failure. The procedures assume power supplies, TSMB,
and the front panel LEDs are working. Suspect the bias cables. Refer to
"Verifying the A2 LOPA, A3 LODA, and A4 Phase Compensation Boards" on
page 4-22.
1. If one or more of the LO ports are working, suspect the LODA.
Keysight N5290/1A Service Guide
Chapter 7
4-23, and Figure 4-14 on page
Figure 4-3 on page
4-25.
Figure 4-3 on page 4-12
and to "Removing and Replacing the Front
7-28.
"Verifying the A5 Test Set
4-9.
Figure 4-3 on page
4-25.
4-12, Figure 4-13 on page
Table 4-1 on page 4-11
thru Figure 4-7 on page
"Verifying the A2 LOPA, A3 LODA, and A4
4-22. Replace the failed
4-12, Figure 4-13
4-23, and Figure
4-16. If the DC
4-27