Agilent Technologies 6890 Series, Service Manual, Page: 568 / 867

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Jun 2001
Error Codes and Internal Diagnostics
Agilent 6890 Gas Chromatograph Service Manual
Faults 850
Fault 235—Aux 2 thermal shutdown
Fault 235—Aux 2 thermal shutdown
Status message: Aux 2 temp too hot
The aux zone’s temperature is higher than the maximum allowable
temperature (detector type maximum temperature plus an additional 25
°
C).
This indicates a defective heater drive on the mainboard or a defective sensor.
Power is disabled to the small zones and the oven. This fault can only be
cleared by turning off all the heated zones and turning the instrument off and
on again.
❐
The problem could be caused by a defective sensor or defective heater
driver on the mainboard.
❐
See Fault 221—Thermal shutdown (status message).
Fault 236—Aux 2 thermal shutdown
Status message: Aux 2 temp sensor
Aux zone 2’s temperature reading reports that its temperature is lower than
expected, which indicates a shorted sensor. Power will be turned off for the
zone.
❐
The sensor must be replaced.
❐
See Fault 221—Thermal shutdown (status message).
Fault 237—No line interrupt. Thermal shutdown.
Status message: No line interrupt
The electronics on the main board are not functioning correctly. Power will
be shut off to the oven and other heated zones. The 6890 GC will not be ready.
❐
The main board must be replaced.
❐
See Fault 221—Thermal shutdown (status message).