GC Troubleshooting Guides 

INLETS

6890 and 6850 Split/splitless Inlet Overpressure
This document outlines a logical procedure for troubleshooting a 6890 or 6850 GC that will not equilibrate to the setpoint pressure of the capillary inlet system. The inlet overpressurizes and the actual pressure stays higher than the setpoint. The GC cannot become "Ready for Injection." This is a common problem in applications with high split-vent flow AND low inlet pressure, as required by short 530 um or other wide-bore capillary columns in split mode.

6890 and 6850 Split/splitless Inlet Underpressure
This document outlines a logical procedure for troubleshooting a 6890 or 6850 GC that will not equilibrate to the setpoint pressure of the capillary inlet system. The inlet actual pressure stays below the setpoint (or at 0 psi) and the GC cannot become “Ready for Injection”. The procedures in this document address the class of problems that are generally related to inlet leaks.

5890 EPC Split/splitless Inlet Problems
The purpose of this document is to outline a logical procedure for troubleshooting a 5890 Series GC with and EPC split/splitless inlet that cannot achieve setpoint pressure, is exhibiting fluctuating pressure, or is having a problem with the measured flow not matching the displayed flow.

5890 Series II and Series II Plus Cool On-column Troubleshooting
This document describes procedures to keep your 5890 Series II/Series II Plus COC inlet functioning properly. It includes pressure and temperature control problems; septum, syringe, and vial septum problems; FID flameout problems; peak broadening and split peaks; and more.

DETECTORS

FID Ignition Problems
This document outlines a logical procedure for troubleshooting FID ignition problems, including difficulty lighting the FID, flameouts during injection, and intermittent re-ignition during a run.

FID Noise Problems
This document outlines a logical procedure for troubleshooting FID baseline problems, including noise, high background, drift, or cycling.

TCD Troubleshooting Tips
This document looks at critical performance factors (temperature, flow rate, and filament resistance) for thrmal conductivity detectors and how they impact response.

MS Pump-down Problems
This document describes scenarios that can help isolate problems related to pumping down Agilent mass spectrometers and establishing a good working vacuum.

MS Autotune Problems
There are several things that could cause your mass spectrometer not to Autotune. The most common, easily corrected Autotune problems are listed in this document.

MS Flat or Unresponsive Baseline Problems
Typically, when the baseline goes flat during the run (especially if it seems to stop during a peak eluting), the most common cause is a blown filament in the mass spec source. Other hardware or electronics problems also are considered.

ECD Troubleshooting Tips
Performance problems associated with the Electron Capture Detector include (but are not limited to) loss of sensitivity (real, or perceived), high signal background, noisy baseline, and chromatographic peaks or humps that are not characteristic of the samples being introduced in the inlet. If the problems are not accompanied by an increase in the signal output, as read from the front keypad of the GC, then suspect the detector only after the other parts of the chromatographic system have been checked.

GENERAL

Interfering (Ghost) Peaks
This document outlines a logical procedure for troubleshooting interference peaks on GC. This particular example involves a GC configured with capillary inlet running splitless mode and an electron capture detector (ECD). The sample is a mixture of one pesticide (lindane) in isooctane solvent.

GC Baseline Problems
Baseline problems arise from many causes such as electronic or mechanical failure; contamination in critical areas, such as detectors; incorrect or inappropriate setpoints; leaks, column or septum bleed, or other chromatographic difficulties. Systematically troubleshooting the GC is key to understanding and diagnosing the cause of baseline problems.

5890 Oven Heating Problems
This document outlines various problems and solutions for 5890 oven temperature problems.

AUTOMATIC LIQUID SAMPLER

7683 Troubleshooting Guide
This document contains a list of 7683 ALS faults and error messages, probable cuases, and suggested actions.

7673 Troubleshooting Guide
This guide will help to isolate problems associated with the 7673 autosampler system to help determine the site of the problem, i.e., in the autoinjector (tower), controller, or autosampler tray (if present).

7673 Bottle Not Found
This document outlines various reasons why the 7673 ALS (18596 A/B tray) may be experiencing a "Bottle not found" error.