Agilent Technologies HP 8719D Service Manual page 241

3. Since the analyzer phase locked in lowband, all of the phase lock circuitry is
working Look for low power as a cause of phase lock errors.
4. Check power at S2J3.
If the power at S2J3 is less than 0 dBm, check the insertion loss of S3, S4
n
and the associated cabling.
If the power at S2J3 is greater than 0 dBm, the problem is probably above
n
5 GHz.
Proceed with the next steps.
5. Check all RF cabling and connections.
If any of the cables or connectors are bad, have them repaired or replaced.
n
If the cables and connectors are good, replace the A55 YIG 1. If mid band
n
problems still persist, then replace the A58 M/A/D/S.
High Band Problems: (HP 8719D/2OD Only)
tuning the instrument from about 2.4 to 5 GHz). Loss of lock in high band
only may likely be due to a bad cable or connection.
2. Referring to the overall block diagram, the following components may be at
fault:
n
n
n
n
3. Since the analyzer phase locked in lowband, all of the phase lock circuitry is
working Look for low power as a cause of phase lock errors.
4. Check power at S2J3.
If the power at S2J3 is less than 0 dBm, check the insertion loss of S3, S4
n
and the associated cabling.
If the power at S2J3 is greater than 0 dBm, the problem is probably above
n
5 GHz. Proceed with the next steps.
Source Troubleshooting 7-21