Agilent Technologies 5975C TAD VL MSD, Troubleshooting And Maintenance Manual

Page: 43 / 276

General Troubleshooting
2
5975 Series MSD Troubleshooting and Maintenance Manual 43
Foreline pressure is too low
If the pressures you observe are below 20 mTorr, check for the following:
•
Column (carrier gas) flow is too low
•
Column plugged or crushed by an overtightened nut
•
Empty or insufficient carrier gas supply*
•
Bent or pinched carrier gas tubing*
•
Foreline gauge is not working correctly
* These could create a fault condition in the GC that would prevent the GC
from operating.
Analyzer chamber pressure is too low
If the pressures you observe are below 1 × 10
-6
Torr, check for the following:
•
Column (carrier gas) flow is too low
•
Column plugged or crushed by overtightened nut
•
Empty or insufficient carrier gas supply*
•
Bent or pinched carrier gas tubing*
* These could create a fault condition in the GC that would prevent the GC
from operating.
Gauge controller displays 9.9+9 and then goes blank
This indicates the pressure in the analyzer chamber is above 8 × 10
-3
Torr.
•
Solvent peak from an on-column injection
•
MSD has not had enough time to pump down
•
Excessive foreline pressure
•
Vacuum gauge has failed
•
Line voltage too low
•
Turbo pump is not working correctly
•
Diffusion pump fluid level is low or fluid is contaminated