Keysight Technologies N9030B Service Manual page 209

Front End Control Troubleshooting
A15 Front End Control Assembly Troubleshooting
Input Attenuator A Control Logic Verification (Option 544, 550)
Ignore DS11 in this procedure.
Press System, Show, Hard ware. Look for an entry for the Low Band Switch
and verify that the HW ID is 45. If the HW ID is something other than 45 (for
example, 10) or there is no entry for the Low Band Switch, the analyzer will
control the attenuators as if they are 26.5 GHz attenuators, not the 50 GHz
attenuators that are actually installed. If this occurs, skip this procedure and
troubleshoot the Low Band Switch.
Press AMPTD, Attenuation 0 dB on the analyzer.
Attenuation LEDs DS14 through DS20 should be off.
When the input attenuation is changed from 0 to 8 dB in 2 dB steps, LEDs
DS14 through DS16 should be illuminated as per
attenuation is set to 70 dB, LEDs DS14 through DS16 should all be illuminated.
Table 6-6
Attenuator Setting
(dB)
If this is incorrect, the most probable cause is the A15 Front End Control
Assembly.
N9030B PXA Signal Analyzer Service Guide
Input Attenuator A LED's (Opt 544, 550)
DS14
0 OFF
2 OFF
4 ON
6 OFF
8 OFF
70 ON
Table 6-6. When the input
DS15 DS16
OFF OFF
ON OFF
ON OFF
OFF ON
ON ON
ON ON
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