Chapter 5 Service
Self-Test Procedures
105
5
606
Rundown gain out of range  This test checks the nominal gain between the 
integrating ADC and the U19 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 U19 on-chip ADC. The gain test (606) is performed 
eight times. Gain noise must be less that ±64 lsb’s of the U19 on-chip ADC.
608
Serial configuration readback failed   Th is t es t r e- s en d s th e la s t 3  b y te  se ri al  
configuration data to all the serial path (SERDAT, SERBCK, SERCLK). The 
data is then clocked back into U20 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 U23.
624
Unable to sense line frequency   This test checks that the LSENCE logic 
input U19 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 U19 and U1 through the optically isolated (U2 and U5) 
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 U1 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 U19 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 c heck s the sta tus of volta g e and  cur rent er ror 
amplifiers for the power circuit. If both amplifiers are not operational, the 
power supply will beep and the error annunciator will be on.