Agilent Technologies 6890 Series, Service Manual, Page: 569 / 867

850 Faults
Fault 238—Faulty line interrupt. Thermal shutdown.
14 of 22
Jun 2001
Error Codes and Internal Diagnostics
Agilent 6890 Gas Chromatograph Service Manual
Fault 238—Faulty line interrupt. Thermal shutdown.
Status message: Line interrupt
The electronics on the main board are not functioning correctly or there is
an excessive amount of noise in the power supply to the instrument. Power
will be shut off to the oven and other heated zones. The 6890 GC will not be
ready.
❐
Turn the 6890 GC off and then on again. If the problem was caused by
noise in the power supply, the instrument will operate normally again.
If the error persists, the main board must be replaced.
❐
See Fault 221—Thermal shutdown (status message).
Fault 239—Mux ADC thermal shutdown
Status message: No mux ADC response
The multiplexor, which processes the 6890 GC electronic signals, is not
functioning. Most likely, the multiplexor’s circuitry is defective. 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).
Fault 240—Mux ADC thermal shutdown
Status message: Mux ADC offset value
The multiplexor, which processes the 6890 GC electronic signals, is not
functioning. Most likely, the multiplexor’s circuitry is defective. 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).
Fault 241—Line sense reading thermal shutdown
Status message: Invalid line sense