Mutoh VJ1204 Print problem missing half black

[lostbay]

Mutoh VJ1204 Everything is perfect except the one section. Done everything except new print head. Would appreciate any suggestions before I start throwing more money at it. Thanks!

 

[Solventinkjet]

Usually when only 1 channel fails on that model, it's a bad damper or a broken manifold. When you changed the dampers did you also change the o-rings? If not, I would start there. Also, inspect the nipple where the damper connects to the head and make sure it's not cracked or damaged in any way. The manifold is replaceable and a lot less expensive! A good way to troubleshoot is to simply swap the black damper's positions, run a cleaning cycle and then another test print. If the channel that wasn't printing before still isn't printing, most likely your head is fried. If the problem moves however, it could be an air leak or plumbing issue above the head that is causing the issue. It could also just be clogged in which case a good head soak and strong cleaning should help if not a full on manual flush with a syringe.

Take a look at our site for parts if you end up needing something! We offer free support!

 

[lostbay]

Thanks for the reply! Switched dampers. Still the same problem in the same spot. I've tried soaking and flushing the head with little to no change. Immediately after soaking, It prints better, and I get about 80% of that section back, but it almost immediately degrades on the next test.
Just to make sure I'm not screwed up - which has happened once or twice before - when we talk about the "O-Rings" with the dampers, which O rings are we talking about? A pic would be helpful if available.

 

[Solventinkjet]

I don't have a picture off hand but it's a little rubber ring that seals the gap between the ink line and the nut that attaches the ink line and damper.When you take the nut off the damper you can push the nut up the ink line and it will expose the o-ring. They tend to flatten out and cause air to get in over time when they are old.

 

[lostbay]

I don't have a picture off hand but it's a little rubber ring that seals the gap between the ink line and the nut that attaches the ink line and damper.When you take the nut off the damper you can push the nut up the ink line and it will expose the o-ring. They tend to flatten out and cause air to get in over time when they are old.

OK - got it. I had the right O rings.

 

[lostbay]

Replaced the print head. This is what I got for my first nozzle checks - nothing else changed.

 

[greysquirrel]

make sure the data cables are seated properly...

 

[lostbay]

Victory! Removed the cables from the head, gently scraped them with a razor blade, reinserted them and she's now printing like the day she was born! Not sure what the problem was, didn't see anything come off of them, but there must have been a contaminant of some sort.
Thanks for all the input.

 

[scott dunacn]

Mutoh VJ1204 Everything is perfect except the one section. Done everything except new print head. Would appreciate any suggestions before I start throwing more money at it. Thanks!

i have the same problem have you got your printer going

 

[scott dunacn]

Replaced the print head. This is what I got for my first nozzle checks - nothing else changed.

 

[scott dunacn]

did you buy a new print head or put the old one back in

 

[lostbay]

Got a new print head. The old print head was in bad shape. Printer's like new again.