Agilent Technologies 6850 Series II User Information page 94

FAULT 218
Possible causes:
FAULT 220
Possible causes:
FAULT 221
Possible causes:
FAULT 222
Possible causes:
Released: March 2004
TCD filament short
Wires from detector not connected properly to detector board
Defective TCD cell
The resistance of the filament is too low. This could be caused by a worn or
sagging filament, or if the TCD wires are not connected properly to the
detector board or are touching each other, or if the ∆ PRT wires are not
properly connected to the detector board. The detector will not be ready until
the condition is corrected.
Heater overcurrent
To clear the error message, turn off all the heated zones and turn the GC off
and then on again.
Shorted heater
Defective main board
Wrong heater (heater power > 70W)
A heater in one of the small heated zones tripped an over-current safety
circuit. There is a short in one of the heaters, or the heated zone's electronics
are defective. This error does not indicate a problem with the oven. Power to
the small heated zones is disabled.
Thermal shutdown
To clear the fault, turn the GC off, then on.
Defective main board
Shorted temperature sensor
Shorted heater
Wrong heater (heater power > 70W)
A thermal shutdown fault disables power to the oven and other heated zones
(inlet, detector, aux). The GC will be not ready.
Oven temp too hot
Defective oven temp sensor
Defective main board
The oven temperature reading indicates the oven is >25 xb°C above its
maximum allowable temperature. Oven and other heated zone power is shut
down. The GC will be not ready.
To determine if the oven sensor is broken, test its resistance. The resistance
will be 100 ohms if the sensor is working correctly; a much larger value indi-
cates a faulty sensor.
6850 Series II GC User Information
Messages
Fault messages
page 94 of 256