Agilent Technologies 8753ES Option 011 Service Manual page 277

Check 2nd LO Signal at Sampler/Mixer
Check the 2nd LO signal at the pins identified in
Check" on page 7-12
illustrations. Table 8-3
Table 8-3 2nd LO Locations
Mnemonic Description
2nd LO 1 2nd LO (0 degrees)
2nd LO 2 2nd LO (−90 degrees)
If the 2nd LO is good at the sampler/mixer, the sampler/mixer assembly is faulty.
Otherwise, troubleshoot the A12 assembly and associated signal path.
Chapter 8
for analog bus and oscilloscope checks of the 2nd LO and waveform
identifies the signal location at the samplers and the A12 assembly.
Sampler
Location
A4/5/6 P1-11
A4/5/6 P1-4
Troubleshooting When One or More Inputs Look Good
Table 8-3. Refer to the
Signal Source
A12P1-2, 32
A12P1-4, 34
Receiver Troubleshooting
"A12 Reference
8-13