Chapter 5 Service
Self-Test Procedures
100
605 Cannot calibrate rundown gain This test checks the nominal gain between
integrating ADC and the U17 on-chip ADC. This error is reported if the
procedure can not run to completion due to a hard ware failure.
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 on the top board 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 U11 on the top board.
624 Unable to sense line frequency This test checks that the LSENCE logic
input U17 on the top board is togging. 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 U16 on the top board and U10 on the bottom board
through the optically isolated (U1 and U2 on the bottom board) 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 U10 on the bottom board 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.
631 Syst em D AC tes t fa ile d 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.