JV3 printhead manifold swap?

[MikePro]

after chasing reoccurring ink supply issues, I have to assume that the problem is within the head. My test prints come out clean, after long soaks manually drawing on a syringe from the waste line (at which point I hear the distinct sound of air escaping somewhere within the head carriage), but my cyan drops out after the first couple of passes. At first I thought it was a pump issue, but after cleaning the lines/pump and swapping the Y and C waste lines the problem stayed with the cyan.
No air in lines, everything's good through the dampers, and installed a new capping station but still hear a hissing noise when I draw on the line with a syringe. KMY lines draw just fine but cyan is getting whisps of ink droplets.

Correct me if you think its another issue, but I strongly feel that I have a cracked manifold (or a bad connection, somehow) that's not holding a seal and starving my ink supply with an air leak... or at least i'm praying so, since I have 3 from old printheads that I can use as parts to swap-out.

I've installed 3 printheads so far, so I'm not worried about that portion, but I've never taken the manifold off and swapped to another before....
is it as simple as just taking off the two screws and capping on top of another printhead?
i notice there's a rubber seal on the printhead that the ink channels simply sit on top of and assume its just a pressure fit. looks pretty simple, re-aligning is gonna be a pita but I gotta do what I gotta do right?

any tips would be great, as I wouldn't be surprised if I'm missing something here. ready to outsource the rest of this car wrap and buy another printer if I go through all this just to find that I destroyed a perfectly good printhead, lol. (i'd rather wait until the ISA show this spring for my next big purchase, tbh.)

 

[genericname]

Replacing the manifold is as easy as you stated. Chances are, if you checked everything, the hiss and loss of pressure is indeed either from a cracked manifold, or busted o-rings. Lately, my number one ink dropout issue has been due to cracked manifolds.

No tips really, other than to make sure you transfer your head ranking sticker from the old manifold to the new one, to avoid confusion in the future.

Good luck with the realignment!

Edit: Oh! And do make sure that you've also seated the rubber gaskets that go between the manifold and head. THAT would be a hell of a mess.

 

[artbot]

pick up an automotive stethoscope to hear if the leak is above or below the head. the difference will be obvious. have a partner pull at the waste line and move above and below the head as close as you can to the part. you'll need to be about 1/8" away. one will be a screeching loud hiss the other a faint hiss.

one way to check for a cracked manifold while the head is still on the carriage is to attach a pump tube (power down, unplug etc) on each manifold nipple. put some light positive pressure into the head. does the little mote fill up with cleaning solution around the nipple? if so that manifold is cracked. some manifolds have a hair line fracture, invisible to the eye but will kill the ink flow to that head.

 

[MikePro]

sweet, thanks guys!

@ artbot: thanks again for the tip, i never got around to picking up the stethoscope last time you posted about it, since I just went straight to the lesser of all evils (capping station) and was certain I had fixed the problem. This time around I'm getting one, if anything to make sure i'm absolutely certain before pulling the head.

also, great tip a few months ago about keeping the old printheads around after swapping! Already ripped the manifold off the head that was beyond any good use, and still have 2 dummy heads for future diagnosing!

 

[MikePro]

still boned: longstory short, swapped the manifold, still hear air leak.

initial test prints came out perfect! but I assume it was because I had taken the opportunity to flush the head with cleaning solution and primed it with cyan ink. test draws gradually lost more and more % of the grid, damper on left channel is now half full of air.
maybe something as simple as a damper swap? i picked up the stethoscope, but I still cannot hear anything better than without it. maybe it wasn't a cracked manifold after all? idk, i'm out of ideas and burned out from working on this thing nearly allday.

time for a burrito and some tequila before startin' fresh in the a.m.

 

[genericname]

Hate to sound like a broken record, but did you try replacing the o-rings between the lines and the damper? I had a veeeeeery small leak once due to it, that was causing huge print issues.

Also, did you try drawing ink from the line? What's the pressure like in comparison to the other lines? If it's fighting you hard, the pin or seal for the pin in the cartridge assembly may be borked, causing negative pressure, and sucking air through the head, leaking ink inside of the cartridge bay.

Edit: Old before my time; forgot about your earlier mention of pulling from the lines. Oy.

 

[MikePro]

passed on the tequila, but the burrito gave me the energy to pull a late-nighter taking the printer apart (again!).

TADAAAA!!! PROBLEM SOLVED!
solution: gave another go at the capping station, this time pulling the cyan cap and giving it another thorough cleaning... still an air leak, ugh. Soooo I pulled the rubber cap off and just barely reseated it, allowing the printhead to press it into place when I pushed the carriage back to the "park" position. Suddenly I'm able to draw ink through the waste line with NO AIR LEAK! Also, pulling some of the slack in the waste line through the pump made a drastic improvement in the amount of "draw" through the line!
happy day!

granted, my cyan test print is and has been showing some degradation and overnight soaks have corrected it (nor flushing during the removal/reinstall). Also, during the process of pulling the head, i noticed a scratch in the middle of the head, and wiping it with a clean foam swab+solution revealed that the head wasn't displacing the fluid evenly nor quickly (hard to explain, but I've seen it work "properly" on a new head, where the solution will disperse itself rapidly to the outer perimeter of the head into the "moat" but this head seems to flow at about half the speed, and breaks apart into a "J" rather than an "O")... so most likely time for a new head anyways, but since I hadn't run any alignment procedures, yet, I'm most likely going to buy myself some time and swap the black and cyan heads since a 100% functional black head is less important to my prints than a cyan. (even when printing black, its still using more CMY than black ink)

 

[MikePro]

oops, meant to say overnight soaks haven't corrected the displaced nozzles. ...and its never the same ones, they keep moving between channels up/down/left/right. nonetheless, i still couldn't be HAPPIER! currently prints are coming out just as good as if nothing was wrong!

 

[artbot]

man mikepro you are getting from his issue. i remember when i had this issue for a while. turned out stretching the capping station springs solved it. i guess you've already painted the tops of your caps with ink to make an imprint on the bottom of your heads to look for cap targeting. also, during wiping, if a wiper is set too low it can just plaster the next head with latent ink instead of wiping it clean. this can cause nozzles out. if the nozzles out is constantly moving about, that is almost always a sign of bad cap seal.

so, it's working? kinda working?

 

[MikePro]

aye, its working! seal is perfect now, pump is drawing ink outta the cyan just like the other heads that are 100%. ...which was the main issue in the first place.

new issue now is that I think the cyan head is starting to go, as i'm getting flashbacks of symptoms prior to my past issues ending with eventual massive overspray.
i.e. fuzzy nozzle checks and missing nozzles appearing/disappearing all over the test print like a game of whack-a-mole.
most likely a result of a slight scratch i see in the middle of the printhead, but like i said in an earlier post in this thread, wiping the head itself with a clean swab + solution reveals that the liquid doesn't spread out across the head quite as fast/evenly as its supposed to. its most likely just getting old and time to replace.

 

[artbot]

me too on the cyan. my media clip has a cloud of cyan on it. which to me means, that even though i can't see the latent cyan overspray in my prints, it must be happening slightly. thus accumulating on the clip. and what is it with cyan. that seems to be a problematic color.