Z3200 ink starvation

[Photoworx]

We "never" have print quality issues with our Z3200; now we have one that is proving intractable.

Printing a 24" x 36" poster that has a mostly gray background.  Got most of the way through the poster then got significant banding, with lighter areas.  The diagnostic print showed many dropouts in light gray, so did a head cleaning for the LG head.  Another diagnostic print showed the problem was fixed, so we reprinted the job -- only the banding was worse.  I removed the print head and cleaned it with a damp paper towel.  I cleaned the printhead contacts in the sled with a swab and isopropyl alcohol.  Put it all back together.  The head alignment print showed no banding, so I restarted the job.  The banding is as bad or worse.

It sounds like the ink starvation Mikeg81 discussed in another thread.  But while he listed the potential causes, he didn't list any potential remedies or any ways one could isolate the problem.

Additional information: I changed driver settings and reprinted the job.  I checked the Maximum details and More passes boxes in hopes that they would slow the printer down enough to avoid ink starvation.  It worked.  The job printed without any dropouts.  Which is both good news and, to me, further evidence that the problem is caused by the printer not being able to get ink to the heads fast enough.

So I'm still looking for advice on how to isolate the cause of the starvation and fix it.

[davidzuts]

This is usually a sign of air in the ink tubes for that color. First you need to remove the air and I use a syringe to draw ink to make sure no air is in the tubes. The second thing you need to do is replace the printhead. Once the head gets air the problem will only occur again, plus not replacing the head usually creates air in the tubes again.

[Photoworx]

David, at the risk of sounding obtuse, how does one use a syringe to get the air out of the tubes?

[davidzuts]

Remove the printhead with problem. Take syringe and put needle into front where pin from printhead goes in. Draw the plunger of the syringe up to force ink into the syringe. Usually 5-10 ml of ink drawn is enough to clear any air pockets in the tubes.