4-46 Keysight N5224A/25A Service Guide
Troubleshooting
Measurement System Troubleshooting
4-
—
Port 2; W104 of A49
—
Port 3; W100 of A47
—
Port 4; W102 of A48
2.
Disconnect the appropriate semirigid cable from the output of the step
attenuator.
3.
Connect the spectrum analyzer to the open step attenuator connector. Set
the spectrum analyzer to measure a signal at 800 MHz.
4.
If the 800 MHz signal is not present, replace the receiver step attenuator.
Refer to
“Removing and Replacing the A38–A41 Source Attenuators and
the A46–A49 Receiver Attenuators” on page 7-45
5.
If the 800 MHz signal is present, replace the associated mixer brick, A27 or
“Removing and Replacing the A27 and A28 Mixer Bricks” on
.
Checking the A24 IF Multiplexer Board
1.
Locate each of the flexible RF cables at the output receivers of the IF
multiplexer board:
—
2-port models
—
Receiver A; W69
—
Receiver R1; W72
—
Receiver R2; W73
—
Receiver B; W70
—
4-port models
—
Receiver A; W69
—
Receiver B; W70
—
Receiver C; W72
—
Receiver D; W73
—
Receiver R; W71
2.
Disconnect the appropriate flexible RF cable from the output receiver to be
tested on the A24 IF multiplexer board.
3.
Connect the spectrum analyzer to the open connector.
4.
. The measured signal on the spectrum
analyzer should be at 7.61 MHz (analyzers with DSP version 4.0), or 7.44
MHz (analyzers with DSP version 5.0), and 1 GHz.
5.
If the measured signal is present, replace the A16 SPAM board. Refer to
“Removing and Replacing the A4–A17 Boards” on page 7-14
.