Looking for suggestions, not seeing the standard reference masses for 6545 QTOF. Plenty of reference mass prepared, reference mass checked on in method and the check valve is open.
We did find a blockage in the line between the bottle and nebuliser, which we flushed with a syringe. Doing the flush has allowed us to see the reference mass again, though the abundance is 3 orders of magnitude less than expected. We are using a fresh solution from a stock preparation made in September.
The instrument was off for a period due to an unrelated failure in the lab's UPS.
I can not see any spray currently and we are thinking that the nebuliser, may also have a partial blockage.