280 Keysight N9038A MXE Service Guide
Front End Control
A15 Front End Control Assembly Troubleshooting
15.Change the Mechanical Attenuator setting to 4 dB by pressing AMPTD,
Attenuation, Mech Atten, 4 dB.
16.Verify that the status of the A9 Input Attenuator A LEDs on the Front End
Control Test board are as shown in Table 8-4 for the Mechanical
Attenuator - 4 dB instrument setting.
If the state of the status LEDs is correct proceed to the next step. If not,
there is most likely a problem with the A15 Front End Control assembly.
17.If no trouble has been found with the control logic coming from the A15
Front End Control assembly, yet there is still a problem with the A9 Input
Attenuator A, refer to Chapter 5, “RF Preselector Section.” for further
troubleshooting information on the A9 Input Attenuator A itself.