Keysight N5221A Service Manual page 118

Troubleshooting
Measurement System Troubleshooting
3. If the measured signal is not present replace the A33 reference mixer switch. Refer to
Replacing the A33 Reference Mixer Switch" on page
Checking the A42, A43, A44, and A45 35-dB Receiver Step Attenuators
1. Locate the appropriate semirigid cable at the output of the receiver step attenuator to be checked:
• Options 219 and 419
— Port 1; W88 of A34
— Port 2; W94 of A37
— Port 3; W90 of A35
— Port 4; W92 of A36
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
Replacing the A34–A37 Source Attenuators, the A38–A41 Bias Tees, and the A42–A45 Receiver
Attenuators" on page
5. If the 800 MHz signal is present, replace the associated mixer brick, A23 or A24. Refer to
Replacing the A23 and A24 Mixer Bricks" on page
Checking the A20 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; W59
— Receiver R1; W60
— Receiver R2; W61
— Receiver B; W62
• 4-port models
— Receiver A; W59
— Receiver B; W60
— Receiver C; W61
— Receiver D; W62
— Receiver R; W63
2. Disconnect the appropriate flexible RF cable from the output receiver to be tested on the A20 IF
multiplexer board.
3. Connect the spectrum analyzer to the open connector.
4. Refer to the IMPORTANT notice on page
at 7.61 MHz (analyzers with DSP version 4.0), or 7.44 MHz (analyzers with DSP version 5.0).
4-40
7-42.
4-23. The measured signal on the spectrum analyzer should be
PNA Series Microwave Network Analyzers
7-40.
7-34.
N5221A/22A
"Removing and
"Removing and
"Removing and
Service Guide N5222-90001