VJ1204 Ink issue

Recently purchased a VJ1204. Pulled ink through the lines with syringes, but the ink seeps back up. I can remove the dampers and pull ink into them, but it does the same thing, goes back. Where else can I pull ink into? I try cleanings and nozzle checks and get absolutely nothing. I have purchased new dampers, cap top, cleaning solvent and wiper assembly. When I got it home, I followed the manual and installed ink cartridges, did a charge. Each color has two lines and where it splits into two lines there are black little caps. Could this be causing an issue.

 

Is there located where the cartridges go in?

 

I notice what sounds to be an air leak until I push this trigger down, then it stops. Is this normal?

 

I can’t confirm if the maintenance station is working correctly or not. I see where the double connector is, but how do I disconnect the lines to try and pull ink through? I am not against replacing the whole maintenance station, just figured I would try and see if small repairs would fix it. I appreciate your help!!

 

How do I pull the hoses out? I see where there are 4 lines that come together and are connected by white plastic piece and screws. Do I need to remove the white piece? Appreciate your help!

 

What is the third hole on the bottom of cap top for? There is also a third line that isn’t hooked up to anything except the little black box on the right of the other picture. Looks to be a nozzle of some sort.