Agilent Technologies 33500 Series Service Manual page 155

Error Message and Meaning
631 Self-test failed; Chan n, sub attenuator <-7.00 to 0.00>dB too low
Self-test failed; Chan n, sub attenuator <-7.00 to 0.00>dB too high
This error indicates the trim DAC inside the waveform DAC (U1801 or
U1501) is producing output outside of the expected range.
635 Self-test failed; Chan n, null DAC gain[idx] too low
Self-test failed; Chan n, null DAC gain[idx] too high
This error indicates the aux DAC output of the waveform DAC (U1801 or
U1501) or its associated analog circuitry is producing output outside of the
expected range. The gain idx of 1 refers to the POS voltage test, gain idx of
2 refers to the NEG voltage test.
640 Self-test failed; Chan n, offset DAC gain[idx] too low
Self-test failed; Chan n, offset DAC gain[idx] too high
This error indicates that the offset DAC (U1702 or U2002) the associated
circuitry is producing output outside of the expected range. In the case of
the offset DAC, the idx polarities are inverted. The gain idx of 1 refers to
the NEG voltage test, gain idx of 2 refers to the POS voltage test.
650 Self-test failed; Chan n, 0dB path failure expected 0dB, measured
value dB
This error indicates the straight-through (no attenuators) path from the
waveform DAC to the ADC input is producing output outside of the
expected range. If this test fails, then the extended attenuator test 655 will
be not be executed.
655 Self-test failed; Chan n, -8 dB pre attenuator path too low
Self-test failed; Chan n, -8 dB pre attenuator path too high
Self-test failed; Chan n, -16 dB pre attenuator path too low
Self-test failed; Chan n, -16 dB pre attenuator path too high
Self-test failed; Chan n, -24 dB pre attenuator path too low
Self-test failed; Chan n, -24 dB pre attenuator path too high
Self-test failed; Chan n, -24 dB post attenuator path too low
Self-test failed; Chan n, -24 dB post attenuator path too high
This error indicates the specified attenuator relay is malfunctioning, or the
attenuator circuitry isn't providing the expected amount of attenuation.
Chapter 6 Service and Repair
Self-Test Procedures
Probable Cause
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