Agilent Technologies E3646A, User Manual, Page: 177 / 211

Appendix Service Information
Self-Test Procedures
177
Service
Information
606
Rundown gain out of range This test checks the nominal gain between the
integrating ADC and the U17 on-chip ADC. The nominal gain is checked to ±10%
tolerance.
607
Rundown too noisy This test checks the gain repeatability between the integrating
ADC and the U17 on-chip ADC. The gain test (606) is performed eight times. Gain
noise must be less that ±64 lsb’s of the U17 on-chip ADC.
608 Serial configuration readback failed This test re-sends the last 3 byte serial
configuration data to all the serial path (SERDAT, SERBCK, SERCLK). The data is
then clocked back into U16 and compared against the original 3 bytes sent. A failure
occurs if the data do not match. This tests checks the serial data path through U29.
624 Unable to sense line frequency This test checks that the LSENCE logic input U17
is toggling. If no logic input detected, the power supply will assume a 50 Hz line
operation for all future measurements.
625 I/O processor did not respond This test checks that communications can be
established between U17 and U7 through the optically isolated (U9 and U10) serial
data link. Failure to establish communication in either direction will generate an error.
If this condition is detected at power-on
self-test, the power supply will beep and the error annunciator will be on.
626 I/O processor failed self-test This test causes the earth referenced processor U7 to
execute an internal, ram test. Failure will generate an error.
630 Fan test failed This test checks if the fan current is flowing. If the current is not
detected at power-on self-test, the power supply will beep and the error annunciator
will be on. Fan test fail could likely induce overtemperature condition in the power
supply.
631 System DAC test failed This test checks if the DAC hardware is functional. The
main controller U17 sends a reference voltage data to DAC and converts the DAC
output to digital data to see if the digital data is within a valid range.
632
Hardware test failed This test checks the status of voltage and current error
amplifiers for the power circuit. If both amplifiers are not operational, the power
supply will beep and the error annunciator will be on.