print head issues and whats the normal lifespan of a printhead?

I don't work for Kornit so I can't tell you what their promise for life of a print head is. I do know that ours seem to have large variance of life cycles.

White is a problem but keeping it running and flushing the heads if they start to clog works well.

Cyan has very few problems.

Black is next to last on the problem list.

Magenta clogs frequently.

Yellow seems to have the worst luck in with clogs. I also noticed that the yellow filters clog more frequently. I can only guess that the yellow pigment is in heavier concentration due to is transparent nature?

For your issue:

First, is this consistently happening with all designs? It's much easier to chase a constant issue than intermittent.

If it's intermittent it may be a wiring issue, corroded plugs or wire insulation causing a short.

If it's consistent then what your design shows looks less like a head problem and more like a data problem. The head is a dumb device that is told to fire and does so. If the head is failing it would be clogged or just missing nozzles.

Your issue is probably due to the dongle on top of the head, or the control boards that the heads plug into, or the computer that is connected to the printer. Those are the parts that are responsible for sending the data to the head. First I'd test the dongle, because it's easy and you definitely have known good ones on hand. Shut down and unplug the machine. Disconnect the dongle from the black head and a head next to it and swap them. Turn the machine back on and do another test. If the streaking is now in the other head, the dongle is the issue. If not, it may be the control boards or the computer.

Kornittech said:

I do not believe it is a print head problem, but rather an electrical problem with a part associated with the print head ie: dongle board, data cable or PCI card.

Click to expand...

I don't miss that, one bit; the board I am holding there is about a $5-6,000 board, from what I was told back when I had to replace TWO of them...





The Kornit machines have an awful lot of critical electronics; even one small part failing can cause the machine to go haywire. I hear they are getting faster and more accurate, when it comes to identifying the issues, though!

The board in the picture is behind the print head block; it was part of an assembly that fried when our fixation pump malfunctioned and sent PT fluid all over our electronics systems.... Fun times.