PCI tune ok, but NCI tune not completing

NCI requires that the ion source is only 150° C. Load the default NCI tune, let the source get cool enough and wait at least half an hour for thermal stabilization and then try again. 

What CI reagent gas is being used?  What is the gas setting in the NCI tune? Should be 40....

Do you have an EI tune to show? Troubleshooting instrument issues in CI is difficult.  The PCI tune ion peak shapes are not symmetrical. 

Thermal stabilization were being done.

CI reagent gas is methane. Its 40% in NCI tune.

EI tune was not done recently. Should I go for it then to troubleshoot?

Hi Paul

I did EI TUNE. Thats completely fine. See attached. What should be my next step?

This tune ion peak splitting of all three peaks is not completely fine.

This same symptom shows on the PCI tune as well.  The sort of step in the left side of the 599 peak, the super sharpness at the top, and the split 600 isotope peak are not right. 

Please take a look at this: (+) Quadrupole DC Polarity - what it means and how to check it - Files - GC/MS - Agilent Community

Thermal stabilization at the required 150° C was not done for the NCI tune, it shows that the source was still at 227° C...  The ion source takes at least thirty minutes to an hour after cooling down to 150° C to be stable and the NCI tune to work properly.

Try those and post back.

Checked DC polarity in the sideboard. Its matching with the method.

I followed every guideline. I also replaced the filament. Now all tunes are completing. See the attached tune files.

I wasnt considering replacing filament earlier as methane pretune and pci tune were completing. Which point is indicating that the filament should be replaced?

Btw, thanks a lot for your sincere help and guideline.

It's often difficult to tell when to change filaments. It depends on use, samples, gases, gas cleanliness, and number of tunes.  Certainly inspect them when the source is out for cleaning. If the wire is smooth and clean it's fine to reinstall. If the wire is pitted, bent, or discolored it should be replaced for sure.