Troubleshooting 150
6
Leak from needle
wash system
Loose or overtight-
ened compression
fitting
Verify fittings and ferrules for
under/overtightening and wear.
Replace if necessary.
Defective fluid valve Replace fluid valve (call Waters).
Defective needle wash
pump
Replace needle wash pump (call
Waters).
Autosampler is
siphoning solvent from
needle wash reservoir
Lower the needle wash solvent
reservoir.
Sample injection
problem (such as
sample not being
injected, abnormal
peak shape)
Defective injection
valve
Purge the autosampler. If problem
continues, repair/replace the valve.
Blocked needle due to
particles in sample
Purge the autosampler to unplug the
needle. Ensure sample and solvent are
properly filtered (see Section 4.2.1,
Preparing Samples) to prevent further
blockages. If the problem continues,
replace the needle assembly.
Air bubble in syringe
or sample loop
assembly
Purge the autosampler.
If air bubbles are repeatedly being
drawn in, verify that a vacuum is not
being created when needle pierces the
self-sealing septum (indicating seal is
too tight around needle). Inject from
the sample vial without a cap in place.
Injection from empty
sample vial
Compare sample vial entry and vial
position. Enter correct sample vial
number.
Insufficient sample in
vial
Ensure minimum sample volume
requirement is in the vial (see
Appendix D, Selecting Sample Vials
).
Sample injection
problem (continued)
Cap is on too tight on
the self-sealing
septum
Loosen the cap.
Sample too viscous Dilute sample or decrease syringe
draw speed rate.
Table 6-8 Autosampler Troubleshooting (Continued)
Symptom Possible Cause Corrective Action
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