Agilent Technologies 6890 Series Service Manual page 570

The line sense circuitry on the mainboard is not measuring the line power
correctly. Since it is indicating the power supply is not within acceptable
limits, the power to the heated zones is disabled. Turn the zones off to clear
the error.
Most likely, the main board must be replaced.
See Fault 221—Thermal shutdown (status message).
Fault 242—Pneu aux module invalid constants
Fault 243—Pneu aux module invalid constants
Fault 244—Pneu aux module invalid constants
Status message: Aux 3 faulty fact cal or Aux 4 faulty fact cal or Aux 5 faulty
fact cal
Two conditions could cause this error:
• The module installed in the aux position is not an aux module.
• The aux module is not working correctly; for example, the EEPROM could
be an unsupported version.
Module will not be usable.
Remove the module from the aux position and install the correct module.
Fault 245—Front det module: obsolete EEPROM
Fault 246—Back det module: obsolete EEPROM
Status message: F det module rev or B det module rev
The front or back detector's EEPROM is not recognized by the 6890 GC. The
module is unusable.
The version of the module is not compatible with the version of the
6890 GC.
Jun 2001
Fault 242—Pneu aux module invalid constants
Error Codes and Internal Diagnostics
Agilent 6890 Gas Chromatograph Service Manual
Faults 850
15 of 22