Chromatography Forum

The pump works, but solvent is not went. What can it be?

Possible causes :

Broken piston / pistons ( since LC-10AD has double pistons )
Checkvalves ( especially inlet checkvalves )
Clogged mobile phase filter

The most possible cause is the inlet checkvalves.
Loosen and remove the nut at the outlet checkvalves and try to suck the mobile phase from here with a plastic syringe , then fix the nut and try to pump the solvent.

It indeed looks like a check valve problem. Happened to our shimadzu several times, especially when people used phosphate buffers.

Thanks for the advice. I cleaned IN check valve in an ultrasonic bath with isopropyl alcohol and it solved the problem.