GC 7810A starts running before pressing the 'start run' button on the machine.


We are using GC 7820A and it was waiting for pressing the 'start run' button on the machine before, but suddenly it started running by itself when we press the 'run sequence' on sequence table as soon as machine is ready. we are manually injecting samples and normally, we press 'run sequence', take the sample, inject it and after injection we press 'start run' on the machine. 

which setting that we may accidentally changed, causes this problem?

  • It sounds like the injection source was changed.  Where this is configured would depend on the software program you are using.  For some of our software platforms:

    Chemstation: Instrument menu > Select Injection Source

    MassHunter: Instrument menu > Inlet/Injection Types

    OpenLab 2.x: specified in the sequence

    In all three cases the injection source should be set to manual or external.

    Another possibility is that the vial number field in the sequence is blank.  In this case, the software treats it as a blank run and doesn't wait for the start signal.  (This would apply to Chemstation & OpenLab 2.x.)

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