I have been working on the Carlo Erba\Fisons\Thermo EA systems for 15 years
and I am positive I can fix your problem. The first thing to check is the
indexing arm on the left side of sampler. There is a bracket around it and if it is
too far foward the indexing arm might not click into the next tooth on the
gear consistently. The way you describe the problem if it is always the second
sample of a run and always position two on the tray you might have a bad tooth
on the gear. If the problem is always the second sample but not always
position two on the tray you may just need to clean the Teflon slide. I service all
Carlo Erba\Fisons\Thermo EA systems and have any parts you may need. Contact me
with any questions or comments you may have.

Mike Elefante
Elf Analytical Services
732-922-8400