Mimaki CJV150-160 Repair or new print head?

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Hi all.

I have a Mimaki CJV150-160. Its been an incredible machine for us for the past 4 years. Meticulously maintained, loved, and never ran hard. It worked perfectly until I moved it. I had the machine in a climate controlled room inside my shop in Southern California. I moved the machine as gently as possible inside my cargo van, keeping the temperature above 50º. Once at its new home about 900 miles north I put it in a climate controlled room in my cold garage. I fired it up and ran a test print. The test print is now missing the entire magenta channel on the right side, not even one nozzle. All other channels (including magenta on left side) print perfectly, not a single missing nozzle. I am trying to identify the problem.

So far I have done overnight head soaks, cleanings, Ink fills, swapped the dampers on either side; they print no problem, moved and reconnected the ribbon wires, Ran a small print job. Still no magenta in the test print on the right side.

Does anyone here have any suggestions or techniques that I might be missing? I am trying to avoid the print head replacement. Those things are crazy expensive for this machine.

Thanks in advance.

btw, there are no Mimaki techs in my area. I am on my own here.

 

[Neil]

You need to verify if it's ink/plumbing related before tackling electrical issues.
You could try swapping the damper with the adjacent one - so unplug damper from the offending magenta channel and plug it into the cyan one next to it.
And Vice versa - plug the cyan damper into the magenta nipple. After a clean or 2, see if the magenta ink fires out of the cyan channel and if the cyan fires out of the offending channel.

Make sure the pump is drawing ink well, cap top seals well, tubes under the cap are clear, not blocked.

 

[Solventinkjet]

Agreed with Neil above. Also, this is a scenario I've seen a thousand times. Your cap top and/or pump might have been already failing but working enough to keep ink inside the head. Then when you moved the printer, air got into the system, which is normal, but the failing cap top/pump can't bring it back. So if the cap top is older than a year, you might just need a new one. And as Neil said, make sure ink is actually flowing during cleaning cycles. If not, that's a sign of a cap top as well.

 

[Active Sign]

Agreed with Neil above. Also, this is a scenario I've seen a thousand times. Your cap top and/or pump might have been already failing but working enough to keep ink inside the head. Then when you moved the printer, air got into the system, which is normal, but the failing cap top/pump can't bring it back. So if the cap top is older than a year, you might just need a new one. And as Neil said, make sure ink is actually flowing during cleaning cycles. If not, that's a sign of a cap top as well.

Thank you Neil and Solventinkjet. I was suspicious of the captop. I ordered a new one Friday and am waiting for delivery. I will replace that part and see where it gets me. The waste line is clear, solvent drops right through it when I fill the captop. The damper swap gave me the same results, the colors changed over after a cleaning and printed fine but I am still missing the far right channel. I am crossing my fingers and hoping this captop change will work.

 

[Neil]

The damper swap pretty much confirmed its not ink/plumbing related.
Therefore it's something electrical.

Solventinkjet can help better than I, but I suspect the next thing to check would be all connections.

You say you removed the ribbon connector. If it was just from the head, you'll need to also remove/inspect/replace at the slider board end.
Also the one that connects to the slider board from main pcb.

Follow all precautions before doing anything like this. (dissipate capacitors etc.)
Be super careful plugging in the ribbon cables. You can do it twice and get different results each time!

 

[Active Sign]

The damper swap pretty much confirmed its not ink/plumbing related.
Therefore it's something electrical.

Solventinkjet can help better than I, but I suspect the next thing to check would be all connections.

You say you removed the ribbon connector. If it was just from the head, you'll need to also remove/inspect/replace at the slider board end.
Also the one that connects to the slider board from main pcb.

Follow all precautions before doing anything like this. (dissipate capacitors etc.)
Be super careful plugging in the ribbon cables. You can do it twice and get different results each time!

Update: I replaced the captop and still have made no progress. I removed and inspected ribbon cables on the head and where they connect on the board. I ran a cleaning and watched the head shoot ink with a flashlight, all shoot but that magenta on the right side. I have run ink fills and watched the plastic on the side of all of the dampers fill/bubble out slightly and suck in. So ink is passing through that channel. Its just not getting a electrical signal to print. Could it be the head is just fried on that channel? I remember now that there was a power outage mid print job one day and it completely shut down the printer and RIP computer. The printer and computer were plugged into a surge protector/power strip. Could this be the culprit? This has happened before with no ill effects.

 

[Neil]

Update: I replaced the captop and still have made no progress. I removed and inspected ribbon cables on the head and where they connect on the board. I ran a cleaning and watched the head shoot ink with a flashlight, all shoot but that magenta on the right side. I have run ink fills and watched the plastic on the side of all of the dampers fill/bubble out slightly and suck in. So ink is passing through that channel. Its just not getting a electrical signal to print. Could it be the head is just fried on that channel? I remember now that there was a power outage mid print job one day and it completely shut down the printer and RIP computer. The printer and computer were plugged into a surge protector/power strip. Could this be the culprit? This has happened before with no ill effects.

Gut feeling is that it's not the head. Nor the result of it shutting down mid print.

You would think it was more likely a result of transporting the printer.
That's why I was thinking connectors.

I have a CJV30 - so the older model.
We have access to the service manual and in there it shows where test points are located (on the main pcb and slider board), along with the resistance readings you should see.

We had a similar issue once and we were able to identify/confirm the problem by measuring the test points.
This was done by someone else - not me.
Somehow, he traced it back to a couple of blown resistors on the main pcb. Swapped them out, tested that the readings were all good, and it all worked again.

I can't tell you much more than that. I do have notes kept about the procedure, but it's a different machine to yours.

You could try contacting Macmedia. (As far as I know), they repair pcb's and should be able to steer you in the right direction about what to do next regarding testing etc.
If you can get to the test points, you might be able to verify if it's A) the head, B) the slider board or C) the main pcb

I've attached the pdf we used, showing test point locations and tolerances for the JV33.

 

[Solventinkjet]

It's pretty rare to have a single channel go out electronically. Usually either the whole head stops firing or it fires erratically. Do a damper swap to confirm. Just swap damper positions and run a cleaning cycle to see if another color will fire in the channel. If another color can fire, it's not electrical.

 

[Impact1]

In these cases I have had success doing a more aggressive ink fill.

If you can get into service mode. I would go into #Adjust > #Head Wash and run a “Fill Up”. This fill up runs for about 6mins which is about 4min more then a normal fill up in maintenance mode. After completing this fill up you’ll need to re-input the initial ink fill settings.

Upon re-start of the printer Select ink type, ink set and then power down. Restart the printer while holding the left and right arrow keys. This will bring you into system perimeter mode. Click the “end” key once and then scroll down until you see ink perimeter 1. In that submenu select “Ink Fill” and change the setting from 0000 to 00ff. Then click the “end” button on the panel until you get back to the main menu. Run a cleaning and then a nozzle test print pattern to check results.

If you are still having issues with that channel you can test the TP points on the slider board in order to detect electrical failure of the print head. You would need a voltage meter.

 

[Active Sign]

I ran some files with heavy reds and got a ton of magenta overspray in the red/white edge areas. Now I am starting to think the head might be toast.

It's pretty rare to have a single channel go out electronically. Usually either the whole head stops firing or it fires erratically. Do a damper swap to confirm. Just swap damper positions and run a cleaning cycle to see if another color will fire in the channel. If another color can fire, it's not electrical.

I tried the damper swap and that channel does not fire.

 

[Solventinkjet]

I ran some files with heavy reds and got a ton of magenta overspray in the red/white edge areas. Now I am starting to think the head might be toast.

I tried the damper swap and that channel does not fire.

If a color that normally fires can't fire in that channel, the head is probably fried unfortunately. The overspray indicates so as well.

 

[Active Sign]

If a color that normally fires can't fire in that channel, the head is probably fried unfortunately. The overspray indicates so as well.

Any deals on a replacement head for this beast?

 

[Solventinkjet]

Any deals on a replacement head for this beast?

You can get the original Mimaki head here: OEM Mimaki CJV150 Print Head

We also carry the head without the memory board and you use the old one from your current head for much cheaper. You can find that one here: DX7 Head (No Memory Board)

We also offer free support so if you get stuck you can always call.

 

[Active Sign]

You can get the original Mimaki head here: OEM Mimaki CJV150 Print Head

We also carry the head without the memory board and you use the old one from your current head for much cheaper. You can find that one here: DX7 Head (No Memory Board)

We also offer free support so if you get stuck you can always call.

Is the memory board transfer difficult? does it come with instructions? I have only done DX4 head changes. This DX7 is a new experience for me.

 

[Solventinkjet]

It is super easy to transfer. It's on the head cover so you just pop it off and put it on the new head. DX7 heads are actually easier to install compared to the DX4 in my opinion. It's a single head so you don't have to align it to other heads.

 

[Active Sign]

I tested the coms on the slider board per the manual instructions. A few tested below 7 ohms which according to the service manual indicates a bad head. So I ordered a new printhead. Crossing my fingers.

 

[Neil]

Could also mean a bad cable or badly plugged in cable.
When we were trouble shooting my machine we had bad readings on some test points, unplugged and plugged the ribbon cable into the slider board and head and then got different readings.

 

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Update: Replaced the printhead the non-oem version from SolventInkjet. Added the memory board from the old head. Works perfectly. The machine printer has been running everyday now. Back to making money.

Thank you everyone for all of the troubleshooting suggestions. Greatly appreciated!

 

[Neil]

Good one. Glad you got it sorted and glad you came back and updated and confirmed the problem.

 

[MadMike_gp]

Hi guys, I have the same problem, magenta sometimes prints, but most of the time it is turned off completely. the engineer said that in the nipple under the damper there is a crack and because of this instead of ink sucked air. i do not understand the principle of operation, tell me, is it really possible ?