Early HS eluters poor peak shape


I have recently run into trouble with poor peak shape (Broad with slight splitting) for early eluting volatiles on a 7890/7697A GC-HS setup. I was able to get a nice sharp peak by moving the same column and using all the same conditions on another GC/HS system in the lab, so I am thinking there is an issue somewhere in the flow path on this particular instrument and not a method setting issue. The 7697A HS passes the pressure/restriction leak test and the cross-port leak test and I am unable to pinpoint any obvious leaks using a leak detector. The Inlet leak check was also run on the GC and the total flow result ends up being negative rather than matching the column flow and I am unsure how to interpret that result. 

My first question is if the inlet leak check and inlet trap check tests on the GC keypad should work as described in the manual even if connected to 7697 HS sampler.

My second question is if anyone has any ideas of what my be causing the problem with the early eluter peak shape issues?


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