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Mutoh 628 no ink after printhead

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Racegrafix

New Member
I have a mutoh 628, I have replaced cap, pump, dampers, trying to get it to print all colors with no luck. Now I replaced printhead, and I can see no movement at all in tubes. Many cleanings, little charges, and zero movement. Tried priming the lines but no change. Tried filling cap with cleaning fluid, no change.
 
Solventinkjet

Solventinkjet

DIY Printer Fixing Guide
If ink isn't moving at all in all colors it means the maintenance station isn't working properly. Make sure you attached the 3rd tube to the bottom of the cap top. That one tends to be forgotten sometimes during installs and will prevent a seal from forming. If that's connected properly, you can test the seal between the cap and the head with a syringe. Just cap the head, hook a syringe up to one of the waste tubes and clog the other (I usually just fold it and tape it closed), and then pull with the syringe. You should feel pull back on the syringe almost instantly and it should want to snap back when you let go of it. If you just pull a bunch of air and get no pull back it means the cap isn't sealing with the head. If you do get suction, you should be able to see ink starting to flow in the lines and eventually into the syringe. If you are able to pull ink into the syringe, you might double check your pump connections to make sure they aren't' backwards.
 
R

Racegrafix

New Member
Solventinkjet said:
If ink isn't moving at all in all colors it means the maintenance station isn't working properly. Make sure you attached the 3rd tube to the bottom of the cap top. That one tends to be forgotten sometimes during installs and will prevent a seal from forming. If that's connected properly, you can test the seal between the cap and the head with a syringe. Just cap the head, hook a syringe up to one of the waste tubes and clog the other (I usually just fold it and tape it closed), and then pull with the syringe. You should feel pull back on the syringe almost instantly and it should want to snap back when you let go of it. If you just pull a bunch of air and get no pull back it means the cap isn't sealing with the head. If you do get suction, you should be able to see ink starting to flow in the lines and eventually into the syringe. If you are able to pull ink into the syringe, you might double check your pump connections to make sure they aren't' backwards.
Click to expand...
I hooked syringe to two lines on cap, I think they are correct ones, the 3rd was a different color. I have no resistance and no fluid movement. I dont hear any air leaks, but pretty gently pulling. I did wet seal.
 
Solventinkjet

Solventinkjet

DIY Printer Fixing Guide
Racegrafix said:
I hooked syringe to two lines on cap, I think they are correct ones, the 3rd was a different color. I have no resistance and no fluid movement. I dont hear any air leaks, but pretty gently pulling. I did wet seal.
Click to expand...
Ok so that means the cap isn't sealing. Make sure the head is in low head height and double check that the head is not crooked in the carriage. I usually push the head carriage over the platen and check the gap between the head and the platen. The head surface and the platen should be parallel. If it looks crooked, you will need to go back in and try to get it to sit flat in the carriage.

Also, if you got an aftermarket cap, that could be the issue. Some work well, others do not.
 
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Racegrafix

New Member
Solventinkjet said:
Ok so that means the cap isn't sealing. Make sure the head is in low head height and double check that the head is not crooked in the carriage. I usually push the head carriage over the platen and check the gap between the head and the platen. The head surface and the platen should be parallel. If it looks crooked, you will need to go back in and try to get it to sit flat in the carriage.

Also, if you got an aftermarket cap, that could be the issue. Some work well, others do not.
Click to expand...
OEM cap. Head is sitting correctly. I can see it has a decent amount of spring tension on cap/head seal when it locks in place. Looking at it, it looks impossible not to seal. Maybe I have the hoses on wrong? I have no idea. I see two nipples on one side and one by itself toward the middle.
 
Solventinkjet

Solventinkjet

DIY Printer Fixing Guide
Racegrafix said:
OEM cap. Head is sitting correctly. I can see it has a decent amount of spring tension on cap/head seal when it locks in place. Looking at it, it looks impossible not to seal. Maybe I have the hoses on wrong? I have no idea. I see two nipples on one side and one by itself toward the middle.
Click to expand...
I assume the dampers were OEM too then? Did you change the connector and o-ring along with the dampers?
 
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Racegrafix

New Member
yes, and yes. I installed the brass nuts on the dampers as well.

I had two colors flowing and after 9 months of trying to get others going I bought print head. Now none flow. I did get ink movement on old printhead, but its been down for a month. (only cleaning fluid in the machine, no ink. )
 
R

Racegrafix

New Member
I keep hearing about a main fuse, but have no idea where thats at. I think I may have cap issue, and if there is a fuse to be blown, and sure its blown.
 
Solventinkjet

Solventinkjet

DIY Printer Fixing Guide
Racegrafix said:
I keep hearing about a main fuse, but have no idea where thats at. I think I may have cap issue, and if there is a fuse to be blown, and sure its blown.
Click to expand...
When the fuse blows it doesn't affect the ink flow in the lines when doing cleanings. So your main issue is the ink flow. Once you get ink flowing to the head, if it still prints nothing, then you can suspect the fuse.

It sounds like the cap top isn't sealing for some reason. Make sure that 3rd tube is connected to it's end point. It's an air release tube so when the head is capped, it doesn't allow air in so the cap can make a good seal. When the head uncaps, it lets air in so the seal breaks and you don't get ink splatter everywhere. If the end of that tube got disconnected from, it just lets air in all the time which would cause this issue for sure.
 
Solventinkjet

Solventinkjet

DIY Printer Fixing Guide
Racegrafix said:
its connected on both ends. It looks like its connected to a small black box.
Click to expand...
That sounds right. Unfortunately it sounds like everything is setup correctly but it's just not sealing for some reason. The fact that you couldn't recover the old head points towards the same thing. It's rare that the cap is misaligned but I would get some black ink on a swab and swab it around the rubber part of the cap top, then cap the head so the ink makes a mark on the head surface where the cap touches it. This way you can take a look at the bottom of the head and see if the cap is actually lining up properly. If the black ink gets on the chrome metal piece that surround the head surface for example, that would cause it not to seal properly.
 
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Racegrafix

New Member
I can see its centered and not on those. I tried the black ink but absolutely couldnt see it, id have to cut the plastic casing off to see it in there.
 
R

Racegrafix

New Member
A few months ago I was told it probably needed the cap, so I installed that and it helped move the ink, but not all colors were printing correctly. This cap has actually never printed anything, only been through cleanings to try to print. On the last printhead I was able to pull ink through it.
I tried sitting a piece of clear plastic on the cap to replicate a head being on it. It pulled down to it, but not very strong, and I could see the seal around it 100%. If felt like an air leak, but 2 ports were sealed and pulling from 3rd.
 
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Racegrafix

New Member
Should I try another set of dampers? Im at a loss, I have spent alot of money and have yet to have any success at all. I have no idea if the 3rd set is oem or not, but at this point im not impressed with anything oem anyway.
 
Solventinkjet

Solventinkjet

DIY Printer Fixing Guide
Racegrafix said:
A few months ago I was told it probably needed the cap, so I installed that and it helped move the ink, but not all colors were printing correctly. This cap has actually never printed anything, only been through cleanings to try to print. On the last printhead I was able to pull ink through it.
I tried sitting a piece of clear plastic on the cap to replicate a head being on it. It pulled down to it, but not very strong, and I could see the seal around it 100%. If felt like an air leak, but 2 ports were sealed and pulling from 3rd.
Click to expand...
It's virtually impossible for all of the dampers fail at the same time. If you're just pulling air at the cap top, that's what's causing the ink not to flow. Do you have the old cap top to throw in and see if it does any better?
 
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Racegrafix

New Member
I threw the old one away, when i installed this one I finally got ink movement again...but clogged printhead. I soaked it for a month, tried everything. Now with the new printhead this is not pulling ink.

I pulled the head, I can see the seal is perfectly lined up. Dampers are not dry. Checked all damper nuts, tight, no change of leaking in my opinion. Head is locked into place perfectly. Primed lines, still zero ink movement.
 
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