Agilent Technologies PNA Series Service Manual page 113

PNA Series Microwave Network Analyzers
E8361A
R1 and A Traces
If both traces are affected, the problem is in the R1 phase lock loop.
• If both traces are missing in all bands, the problem is in the A16 test set
motherboard, the A28 R1 first converter, the A32 R1 receiver, or the A22 switch. To
determine which is at fault:
1. Bypass the A22 switch using a flexible RF cable connected between the input cable W2
and the R1 output cable W4.
2. If the R1 trace is now present, replace the A22 switch. If the R1 trace is still missing,
reconnect the cables to the A22 switch.
3. Swap the A32 R1 receiver with the A33 R2 receiver. (Each of the four receivers is
identical.)
4. If the missing trace is now R2 (still associated with the same A32 R1 receiver), replace
the A32 R1 receiver. If the R1 trace is still missing, replace the A16 test set
motherboard.
• If the trace faults are band-related, especially above 50 GHz, the problem is in the
A23 SOMA 70. Swap the A23 and A24 SOMA 70 assemblies. If the fault is now in the
R2 and B traces, replace the A23 SOMA 70 assembly.
R2 and B Traces
If both traces are affected, the problem is in the R2 phase lock loop.
• If both traces are missing in all bands, the problem is in the A16 test set
motherboard, the A29 R2 first converter, the A33 R2 receiver, or the A22 switch. To
determine which is at fault:
1. Bypass the A22 switch using a flexible RF cable connected between the input cable W2
and the R2 output cable W5.
2. If the R2 trace is now present, replace the A22 switch. If the R2 trace is still missing,
reconnect the cables to the A22 switch.
3. Swap the A33 R2 receiver with the A32 R1 receiver. (Each of the four receivers is
identical.)
4. If the missing trace is now R1 (still associated with the same A33 R2 receiver), replace
the A33 channel R2 receiver. If the R2 trace is still missing, replace the A16 test set
motherboard.
• If the trace faults are band-related, especially above 50 GHz, the problem is in the
A24 SOMA 70. Swap the A24 and A23 SOMA 70 assemblies. If the fault is now in the
R1 and A traces, replace the A24 SOMA 70 assembly.
R1 Trace Only
A problem that affects only the R1 trace is isolated to the A28 R1 first converter, the A32
R1 receiver, or the A6 SPAM board. Go to
R2 Trace Only
A problem that affects only the R2 trace is isolated to the A29 R2 first converter, the A33
R2 receiver, or the A6 SPAM board. Go to
Service Guide E8361-90001
Measurement System Troubleshooting
"Checking the Receiver Group" on page
"Checking the Receiver Group" on page
Troubleshooting
4-52.
4-52.
4- 33