Premiercolour is right, i got some aftermarket, aftermarket, crap from China, rubber was cock stiff whippers were stiff too, I let it soak in oil of winter green and alcohol concoction for a week, rubber came nice and soft they seam to work ok, but i keep a hawk eye on them
Go see your local herorrin dealer and get some syringes, if you have a good flow of ink coming in from the one cap top with little or no bubbles then you be pretty good, if your getting lots of bubbles in the syringe means your sucking air from some were, make sure your cap top is sitting good on the print head, if you pull of the syringe little or nothing come out and you let go the syringe go back in then you have a good seal but something is plugged, do you used cheep ass inks ???
make sure your damper have a good amount of ink and no air in the lines, Check the fuse too but it’s probably fine unless you played with some cables while its pluged in, when you do anything i would make sure you unplug the machine i fine some of them rolands electronic are fragile, i smoked lots of boards rushing and being inpatient
Take you time and make sure everything is right,
Look over your services manual make sure everything is set perfect, i am a bit obsessive compulsive when it comes to that, I often change dampers and cap tops, them parts are cheep, print heads and down time are expensive i have 3 vp-540 so 12 print heads can get expensive hehe
Let us know how you make out
Thanks
Biggs