Mutoh VJ 1204 - Clogs Cleared, Now Only Cyan

[ArtesianGFX]

Picked up a used VJ 1204 the other day that had "clogged black nozzles".

Apparently it say for a while, the guy trying clearing it by pushing fluid through and gave up. Price was good enough for me to give it a whirl and try to get involved in something I'm interested in on a budget. I did the math on replacing things, and it's all well within what I'm comfortable spending on learning a machine and figuring out what I'm doing.

First thing I did was work on the head. Got it all unclogged with a soak and some light push/pull action and now have nice flow gently pushing solvent through on all 8 channels.

Got it all back together and ended up having clogged lines from cap to pump. Got all that cleared and it's pulling ink through for charge and loading all the lines except one magenta. I know that damper is not sealing on the manifold for sure.

On a nozzle check, it seems to only spray 2 cyans and kind of some black.

I checked the typical fuses on the mainboard and those are all good. Cables are seated well.

I'm currently stuck waiting on ink now bacause of the unsuccessful charges and stuff I ran while trying to get flow has convinced the machine that the brand new C and Y are empty.

I'm ordering a complete new set of dampers today and orings for the lines as well as a head cap (just in case).

Anything else I'm missing before I throw a new print head at it?

I've been reading and reading, so hopefully I've exhausted all the avenues before the big repair purchase.

Thanks!

 

[Solventinkjet]

Flushing the head can cause damage internally. If you pushed solution through one channel and it came out of another one at any point during your flush, that signifies damage. When you flush you should be able to see each nozzle spray solution individually as well. You can actually see the missing nozzles. Did you see that spray like that?

I think you're on the right track getting new dampers. If ink is flowing during cleanings, the maintenance station should be good. At the end of the day these heads are very finicky. Sometimes they recover easily and sometimes they are just doomed. It depends greatly on how long it sat, what kind of ink, and how old the head is.

 

[ArtesianGFX]

Flushing the head can cause damage internally. If you pushed solution through one channel and it came out of another one at any point during your flush, that signifies damage. When you flush you should be able to see each nozzle spray solution individually as well. You can actually see the missing nozzles. Did you see that spray like that?

I think you're on the right track getting new dampers. If ink is flowing during cleanings, the maintenance station should be good. At the end of the day these heads are very finicky. Sometimes they recover easily and sometimes they are just doomed. It depends greatly on how long it sat, what kind of ink, and how old the head is.

They were definitely spraying individually with no crossover. I was very very light on the syringe pressure to try to avoid any damage.

After sitting over night, some of the ink lines off the head have new air bubbles. I'm assuming that also points to a bad seal on the dampers?

I almost want to order new head cables since the previous owner had taken them out and put them back in a few times. They aren't shorted and blowing fuses, but maybe they aren't contacting good anymore...

 

[Solventinkjet]

They were definitely spraying individually with no crossover. I was very very light on the syringe pressure to try to avoid any damage.

After sitting over night, some of the ink lines off the head have new air bubbles. I'm assuming that also points to a bad seal on the dampers?

I almost want to order new head cables since the previous owner had taken them out and put them back in a few times. They aren't shorted and blowing fuses, but maybe they aren't contacting good anymore...

Air slowly filling the dampers is a sign that the seal is bad for sure. Make sure to change the o-rings when you change the dampers. They seal the connection between the ink line and damper. When air gets in the system, ink naturally flows back to the cartridge which is counter-intuitive to a lot of people.

Those cables are rated for about 3 in and outs for lack of a better word. If fuses are popping, I'd change those for sure.

 

[ArtesianGFX]

Air slowly filling the dampers is a sign that the seal is bad for sure. Make sure to change the o-rings when you change the dampers. They seal the connection between the ink line and damper. When air gets in the system, ink naturally flows back to the cartridge which is counter-intuitive to a lot of people.

Those cables are rated for about 3 in and outs for lack of a better word. If fuses are popping, I'd change those for sure.

Just sent an order in to you for those parts. Looks like my project is on hold for a bit. Thanks for the advice.

 

[ArtesianGFX]

So, after multiple soaks and cleanings, new dampers and a complete MS, I’m here: