Half full, or 3/4 full in the damper indicate that you don't know how to prime it! There is also a filter screen compartment which need to be filled with ink and no air as well. Many tech do not know how to prime these dampers properly even when they said they have 100 years of experience. In contrary, Genius live fast / die young / do it once and get it right on the first time, every time!
Half full or 3/4 full will work for short while, but only until the siphon start to draw air into the valve and the compression then lost, the valve shut the ink flow. It can even create strange siphoning effect on the other ink lines when displacement occurs inside the capping station suction or when pump is activated during cleaning. Thus, creating contamination and series of unpredict ink flow problems just because you lost the compression or faulty valve(s) on your damper(s).
Once the air is trapped inside the damper, it is unlikely for it to be full with ink inside of it without human intervention. And when the air is trapped inside the damper of the JV33 or JV5, they are like a ticking time bomb, and waiting for you to do that long long banner so the ink flow will quit on you. This is a compression type of damper, it is critical for air to be out of it!
This air trapped inside of damper can even give you more significant problem when doing 4 color mode since the line joined the two ink into one and that trapped air inside the damper will give a faulty valve operation over time; specially when the print head moving back and forth in high speed.
When the Mimaki JV33 or JV5 leave Japan, they all filled with prefill which the manufacturer has already prime all the dampers properly. Just like the human body, there is no air allow in the blood stream in order for the heart to pump correctly. When the air trapped inside the damper, the sealed valve is in the compromising condition and waiting for failure in drawing inks to happen.
In order for JV33 or JV5 dampers to serve inks to the print head, the compression must be establish with total confident which rely on the sealed valve activated by the compression of the circular compartment.
Using after-market dampers will also compromise the rest of the dampers from Japan. Most of the aftermarket dampers do not have the correct seal valve machanism or faulty valve but you don't know it! Buy the genuine Mimaki damper sold by the dealer just to give you the process of illimination to your issue with ink flow (some genuine part also fail in some case just like anything human made).
Also on the top of each damper, it is the long pointing upward that need to be insert into the end cap of the hanging ink lines. This long pointing up PE plastic piece need to be seated inside the end cap for the ink to flow into the damper correctly. It is activate by doing prick and twist
maneuver to allow the locking ink from that top end cap to flow into the damper. Doing this wrong, or using after-market part will prone to faulty seal and the compression valve inside the circular compartment will also fail again.
