Agilent Technologies PNA Series Service Manual page 109

PNA Series Microwave Network Analyzers Troubleshooting
E8361A Measurement System Troubleshooting
SOURCE UNLEVELED: The source ALC circuits on the A12 Source or the A16 Test Set
Motherboard—E8363B and E8364B only—is running open-loop. For the E8362B, replacing
the A12 Source Assembly can repair this. For the E8363B or E8364B, check the cable
connections for W37 and W38 from the A23 and A24 Detectors to the A16 Test Set
Motherboard, and for W39 from A16 to the A21 SOMA 50. If the problem is associated with
one port and not the other, replace the Detector associated with the problem port. If the
problem affects both ports, replace the A16 Test Set Motherboard.
Service Guide E8361-90001 4- 29