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Roland SP300v Cross Contamination Thoughts??

xxxmain

New Member
Hi everyone! I have a common problem that I've dealt with many times and read a lot about on this forum but it's being extra difficult for me this time... cross contamination on my SP300v between the yellow and magenta.

I changed dampers and caps a few weeks ago to address another issue, and the cross contamination started happening. It's mild and only affects the print for the first few inches (the ink is not going all the way back into the lines, and I can't even see discoloration in the dampers). I checked the pump and drain lines and they are all clear. When I changed the dampers all of the ink lines had kinks in them (picture attached), so I cut a small bit off. The problem I think I'm having is the damper o-rings... I didn't have new o-rings so I used the old ones with the new dampers. It started with the magenta contaminating the yellow and after much testing and even changing the yellow damper again, I thought I'd try swapping out the yellow ink (as it had less left in it compared to magenta). Once I put new yellow ink in, the cross contamination started going the other way with yellow into magenta (which makes sense I suppose as the system seems to be trying to equalize and now the magenta is lower).

My question is, could all this be caused by a small leak at the o-ring in the top of the damper? The o-rings don't show any visible damage but they are old and probably squished. I've run extremely different levels of ink always without this problem so it's not simply an ink level issue, but the ink swap showed that the level is affecting the pressure/balance somehow. I don't have any o-rings and I'm trying to source them quickly to try, but I can't find them locally, so wanted the experts thoughts on if I'm zoning in on the right area or should be looking elsewhere? The new caps seem to be good too, as I can draw ink from a syringe below the caps indicating a good seal. Is all this because of damper o-rings??

Also, when I replaced the yellow damper today as a test, it's only filling up the bottom half of the damper with yellow ink (I primed it by using a syringe to draw ink from the magenta/yellow cap line). Should I be filling it full with yellow ink using a syringe directly at the base of the damper or is this "half filled" damper ok? The other 3 dampers are fully filled with ink and I primed them the same way, but did them many weeks ago so maybe the yellow will fill up fully over time too?

As a final note, I can just run 2 cleaning cycles and the cross contamination is cleared showing the ink is not backing up too far (so I have a band-aid solution), but the problem is, by the time I switch that print run to cut, the very next print run (20 minutes later) already has the cross contamination back so it's happening quick and I'm wasting a lot of time and ink between each run.

Someone please tell me I'm an idiot and only need new o-rings!

Cheers
 

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Solventinkjet

DIY Printer Fixing Guide
It could be the o-rings for sure. Might as well try them first. Also, check for any clogs in the lines below the cap tops. There's a Y connector that can get clogged sometimes or even the pump tubes. I usually just flush cleaning solution through the lines with a syringe to test and also clean any partial clogs. If you are using aftermarket caps, I would also suspect those as we've found 3rd party ones tend to not work so well.

Other than that, if ink is flowing correctly and you've got new o-rings in, the head itself might have internal damage.
 

xxxmain

New Member
Awesome, thanks Solventinkjet! I found a 50 pack of o-rings on Amazon with the right dimensions so I'll have those in 2 days (I went with the black Nitrile rubber ones as opposed to the clear silicone ones to try best to match original Roland). I'll also check all the lines and Y's below the caps again to be safe. I am unfortunately using 3rd party caps and dampers... I hope that isn't the problem. But they should all be from the same batch that I've used over the past many years. If all else fails, I'll change all those out again too. The black/cyan aren't cross contaminating, leading me to believe it's something specific to the magenta/yellow side.

Any thoughts on the half filled new yellow damper? Should I just leave it and it'll fill up on it's own or am I best to use a syringe at the base of the damper to fill it up all the way?
 

damonCA21

New Member
It is most commonly down to bad dampers or cap tops not sealing properly, or a problem with the drain lines ( have you also emptied your drain bottle as if this gets too full it can cause it ).

The other thing to check is the o-rings and connections at the ink cartridge dock. If you get a small air link in these it can cause problems.
Ink dampers should full up about 2/3rds of the way, so some air gap at the top is normal.

The other thing I would check is how well the captops are sealing. If you leave the head in the docked position, use a syringe to pull gently on the drain line from the captop. You should feel a lot of resistance, and if you hold the vacuum on it then you will get a slow flow of ink. If the syringe pulls easily then air is leaking into it somewhere. Compare it with pulling on the black/cyan line and they should feel the same.
 
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