Agilent Technologies 6890 Series Service Manual page 561

850 Faults
Fault 218—F TCD filament shorted
board, or the ∆PRT is shorted. (Units made before April 1997 may not use a
∆PRT.)
The detector will not be ready until the condition is corrected.
Check that the wires from the detector are connected on the detector
board.
Check that the ∆PRT is properly installed and not damaged. Replace if
damaged.
The TCD's cell must be replaced.
Fault 218—F TCD filament shorted
Fault 219—B TCD filament shorted
Status message: F TCD filament short or B TCD filament short
The TCD filament bridge voltage indicates that the resistance of the filament
is too low, which indicates a potentially shorted filament. This condition could
be caused by a worn or sagging filament, or if the wires from the TCD are not
connected properly to the detector board or are touching each other, or if the
wires from the ∆PRT are not properly connected to the detector board. (Units
made before April 1997 may not use a ∆PRT.)
The detector will not be ready until the condition is corrected.
Check that the filament and ∆PRT wires from the cell are connected on
the detector board properly.
The TCD's cell must be replaced.
Fault 220—Heater over current. Thermal shutdown
Status message: Heater overcurrent
This message appears when there is a short in the heater of a heated zone, or
when a heated zone's electronics are defective. This error does not indicate
a problem with the oven.
Power to the small zones is disabled. To clear the error message, turn off all
the heated zones and turn the GC off and then on again.
6 of 22
Error Codes and Internal Diagnostics
Agilent 6890 Gas Chromatograph Service Manual
Jun 2001