No Peaks - HP 5973 MSD Hardware Manual

 Troubleshooting
1R SHDNV

No peaks

When troubleshooting "no peaks" it is important to specify what mode of operation
is being used, and what kind of peaks are not being seen. Always start with methane
PCI and verify presence of reagent ions.
No reagent gas peaks in PCI
If MSD has been working well and nothing seems to have been changed
• Wrong tune file loaded, or tune file corrupted
• Wrong ion polarity (there are no reagent ions visible in NCI)
• No reagent gas flow; look for background ions and check pressure
• Wrong reagent gas selected for the tune file (looking for wrong ions)
• Large air leak
• Dirty ion source
• Poor vacuum (pump problem). See page 74.
If MSD was recently switched from EI to CI
• Interface tip seal not installed
• No reagent gas flow
• Analyzer not sealed (big air leak)
• Wrong tune file loaded or tune file corrupted
• Ion source not assembled or connected correctly
• Wrong reagent gas selected for the tune file (looking for wrong ions)
79