I am using an Agilent system with a Quat pump, a VWD, a restriction capillary, and water as my mobile.
No injections were performed. Lamp was exchanged and the flow cell rebuilt. New OBV, rebuilt pump, new capillary, bypassed degasser to check.
Rinsed for a week with water and water/ipa (60/40).These are the results the following week.
These strange dips keep gradually separating and only appear under pressure (holding 320 bar with a 0.3% ripple).