Thermo Scientific Accela Open Autosampler Hardware Manual page 104

6
Troubleshooting
Troubleshooting Using Observed Symptoms or Error Messages
Table 29. Troubleshooting using symptoms and error messages (Sheet 2 of 5)
Symptom or error message
Flow of mobile phase
and/or sample from the
wrong ports on LC
injection valve
Detector signal not
detected or very low
Sample backing up on the
valve needle guide
86 Accela Open Autosampler Hardware Manual
Possible cause
The valve rotor is reversed (180
degrees out of alignment).
Clogged syringe, needle, or holding
loop
Bent needle
No sample liquid injected
Sample volume too low
Improperly installed valve needle
guide, needle seal, or both
Valve ports not plumbed correctly
to the pump, detection system, or
both.
Wrong valve type specified
Syringe OD too small
Leaking valve needle seal
Needle penetration depth set
incorrectly for the injection valve
The syringe plunger speed set too
high, resulting in excessive pressure
in inlet
Recommended action
Remove the rotor and reinstall in the correct
position. For a Cheminert valve, check for
marking points. For a W-type valve, look for a
letter (for example, H) stamped on the rotor. The
letter must be on the lower half of the rotor.
Remove syringe and aspirate/dispense liquid
manually. Clean syringe, needle/holding loop, or
both of these.
Inspect and change syringe if necessary.
Check and adjust Needle Penetration into
sample vial if necessary.
Increase sample volume.
Check valve needle guide and seal.
Check plumbing connections.
Check valve type by choosing Menu > Setup >
Objects > Injectors > LCVlv1 > Valve.
Check the syringe needle for the correct gauge.
Gauge 22 = 0.72 mm OD
Change valve needle seal.
Adjust the injection valve needle penetration.
Reduce inject speed in method.
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