Do you have any diagnosis for this?

[printpros_au]

Hey,

I have a VS640 CMYKLcLmWhMt and suddenly all of the prints are ruined about 2min into the print because the Magenta drops out. It will print the nozzle check and all other tests perfectly fine, but when printing an actual job that has a solid colour that contains magenta (dark blue) it drops out at the same distance into the print each time. And it is like magenta on and magenta off, no grey area.

 

[player]

Damper?

 

[printpros_au]

The issue remains and the Magenta damper has been replaced.

 

[artbot]

start by swapping the magenta damper+line to a different channel and print some big blocks of 100% CMYK see if the issue follows the damper+line or remains at the magenta manifold nipple/channel.

 

[printpros_au]

We tried that and the issue followed the head, could this be caused by the ink or is this an electrical malfunction?

 

[JgS]

air getting drawn into the line? maybe the pump?

 

[printpros_au]

I have tried numerous times performing an 'ink renew' using several different cartridges which proved to make no difference. Just wasted a lot of ink!

 

[Techman]

air leaks,,

 

[artbot]

well, "following the head" can mean following the manifold nipple (cracked possibly) or the manifold prefilter. dx5 heads don't give away as much info in that they have a universal cap. you can always shut everything down and pull a vacuum at the cap/waste line and listen for a vacuum hiss. that is a real quick way to find an issue.

 

[printpros_au]

It is a DX7 head

 

[artbot]

same difference. universal cap vs isolated caps as with dx4

 

[printpros_au]

Sorry I kind of understand what I should be doing but are you able to give me a little more detail, what am I looking for? What could or couldn't be a sign of the problem? Would this be checking the ink flow as an issue, or the head components?

 

[artbot]

to make sure the "damper swap" is done right. confirm that you are not changing out dampers by unhooking them. you need to cross the lines so that perhaps the cyan dampers+lines are plugged into the magenta manifold nipples and the cyan is vice versa plugged to the magenta manifold/channel. set up a CMYK file of block of 100% cyan, and another one of 100% magenta the length of your printer. keep in mind that cyan will come out on the magenta file and magenta, the cyan file. Q: does the magenta drop out plugged to the cyan position? or does the cyan drop out at the magenta position? this will determine if the starvation exists above the manifold or under it.

if the cyan starves, then you might have a cracked manifold or a clogged manifold filter (there's a tiny stainless steel filter inside of each nipple). dunking the manifold in an ultrasonic and forcing cleaning solution will get this back to new. a cheap ultrasonic cleaner can be bought at a harbor freight. sometime, rarely this can be a sign of an issue at the cap's edge. but would more likely occur in a outside position channel.

if the magenta starves at the cyan position then you've got either an air leak breaking the surface tension in the ink line or a restriction (paper from a cart' in the piercing needle, clogged with ink, kinked ink line).

to start looking for an air leak i'd pull a vacuum from the cap side and listen (no a/c, pc fans, anything can be making noise) for a hiss during the vacuuming with a syringe.