Cross contamination

[midnightmadman]

I keep having something strange happen.
One channel of my magenta keeps printing yellow. I do a power clean and it goes back to magenta just as it should. When it sits overnight the same thing happens. It’s always the same one. Thoughts?

 

[Boudica]

I keep having something strange happen.
One channel of my magenta keeps printing yellow. I do a power clean and it goes back to magenta just as it should. When it sits overnight the same thing happens. It’s always the same one. Thoughts?

might be bad heads? I have this issue with our old Roland XR. I do a test print, and I see bleeding, run a cleaning cycle and it's all good, until it sits for a few hours not printing.

 

[Solventinkjet]

Cross contamination happens for multiple reasons. In your case it could be a failing damper. Failing dampers can allow ink to drop out of the head when it's capped and it can get into the adjacent channel that way. It can also happen if the cap top is not draining properly. If your dampers are older, I would just replace them to rule it out. You also might want to flush some cleaning solution through the pump tubes to make sure they aren't partially or fully clogged. If all of that doesn't fix the issue, as Boudica said, it could be the head is delaminated.

 

[midnightmadman]

Strange. Now I have yellow backing into both magenta channels.
Same thing if I run a clean it goes back to magenta. Nozzle check looks fine as except for the the contamination

 

[midnightmadman]

Can I ask also. if the pump tubes are clogged how it could cause this

 

[midnightmadman]

Just An update. Maybe it could help someone else in the future. It turns out it was a clogged drain tube. Had to massage it and work cleaning fluid through. All back to normal.
Thanks.