Keysight N5221A Service Manual page 114

Troubleshooting
Measurement System Troubleshooting
signal path from the output of the source board to the output port.
Set the network analyzer for an S
frequency of 800 MHz.
Perform the following checks in the order presented.
Checking the A25, A26, A27, and A28 Receiver Couplers
1. Locate the appropriate semirigid cable at the output of the receiver coupler to be checked:
• Options 200 and 400
— Port 1; W11 of A25
— Port 2; W23 of A28
— Port 3; W15 of A26
— Port 4; W19 or A27
• Options 219 and 419
— Port 1; W71 of A25
— Port 2; W83 of A28
— Port 3; W75 of A26
— Port 4; W79 of A27
2. Using a 5/16-inch torque wrench, disconnect the semirigid cable at the receiver coupler.
3. Connect the spectrum analyzer to the open receiver coupler connector. Set the spectrum analyzer to
measure a signal at 800 MHz.
4. If the 800 MHz signal is not present and the analyzer does not have mechanical switches, replace the
receiver coupler. Refer to
Brackets" on page 7-36.
5. If the 800 MHz signal is present and the analyzer has source attenuators and bias tees, reconnect the
cable to the receiver coupler and continue testing at
Step Attenuators" on page 4-37
6. If the 800 MHz signal is present and the analyzer does not have source attenuators and bias tees, replace
the test port coupler. Refer to
4-36
S S or S measurement for Port 1, 2, 3, or 4 respectively, with a CW
11, 22, 33, 44,
"Removing and Replacing the A25–A28 Receiver Couplers and Mounting
"Removing and Replacing the A29–A32 Test Port Couplers" on page
PNA Series Microwave Network Analyzers
"Checking the A34, A35, A36, and A37 60-dB Source
N5221A/22A
7-38.
Service Guide N5222-90001