Troubleshooting A Pump That Fails The Flush Air Script - Thermo Scientific EASY-nLC 1200 Troubleshooting And Maintenance Manual

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Troubleshooting

Troubleshooting a Pump That Fails the Flush Air Script

Troubleshooting a Pump That Fails the Flush Air Script
174 EASY-nLC 1200 Troubleshooting & Maintenance Guide
If pump A, B, or S fails the Flush Air script and the Output page displays one of the following
messages, a leak or blockage could be preventing solvent from entering the pump.
• Aborting unable to build pressure
• Aborting check solvent level
Note For information about the Flush Air script, see
The following procedure systematically checks for a blockage in the check valve assembly, in
the solvent line that connects the pressure sensor to the valve, and in the pump head.
CAUTION Wear powder-free gloves and safety glasses when handling parts of the LC system
that come into contact with solvents.
❖ To determine why the pump has failed the Flush Air script
1. If you have not already done so, remove the right side panel of the instrument.
2. Depending on the pump, do one of the following:
• For pumps A and B, go to
• For pump S, go to
3. For pumps A and B, determine whether the check valve assembly is functioning as
follows:
a. Run the Purge script for the pump that has failed (see
b. Check that solvent is being aspirated and dispensed correctly through the Teflon™
lines.
• If the pump is drawing solvent during the fill portion of the purge cycle, the
solvent-side check valve is working properly.
• If the pump is dispensing solvent into the waste beaker during the empty portion
of the purge cycle, the waste-side check valve is working properly.
Note If a check valve is not working properly, replace it as described in
"Replacing the Check Valves"
c. If the check valve assembly is functioning properly, go to
step 3.
step 4 on page 175.
on page 82.
"Flush Air" on page 33.
"Purge Solvent" on
step 4.
Thermo Scientific
page 32).