Replace EM horn?

Hello all,
I recently cleaned my ion source (5977A - Extractor source) and installed two brand new filaments. On my tune report, the EM volts for both filaments are between 1950 and 2005; the gain factor is only 0.389; water and nitrogen are below 4%. Does this seem to indicate that I should replace my EM horn, or is it more likely that there is contamination of some kind? Or something else? The EM volts seem awfully high for two brand new filaments.
Thank you!
Parents
  • What was the EM Voltage before the source cleaning and filament replacement?  How old is the electron multiplier?   They do not typically fail, the tune EMV setting slowly gets higher and higher.  They typically work fine up to ~2500V or so and then the gain curve calculation starts having trouble as there's not enough higher values to use for the calculation.   Could you share a tune report from before and one from after the cleaning?

    Did you clean the source following the instructions in these videos?  (+) GCMS Ion Source Cleaning - Videos - GC/MS Portal - Agilent Community   There is tons of good information there.

  • Attached are tune reports from before and after cleaning and changing the filaments (I was trying to correct chromatographic issues that seem mostly due to a contaminated precolumn and a small leak at the interface between the precolumn and the GC column). 

    I used the cleaning guide "Agilent GCMS Ion Source Cleaning Guide - May 7, 2015" from the Files section on the GC/MS page on this site.

  • Repeller value looks strange in tune report..Even in last report it's zero..

    After cleaning, all wires connected properly?

    Be sure, that atune file is not corrupted..

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