Banding at HP T11xx

[vishop]

Hi Guys,

I have an HP T1100 on site. Whenever they print a certain files/s, banding happens when it reached the center of the paper. I have tried paper advance calibration, calibration of the printhead, cleaning encoder strip, shaft etc, Same thing happen, and banding happens on the exactly same location. If i print other files, it is printing well. If i print internal demo page, it is working fine as well. I tried to print the very same file in our shop machine, HP T1120 and exactly the same kind of banding happens. I cant totally tell that it is a file problem, because if i print the same file on another HP plotter like 4000ps and 1055CM, print is OK, no banding happening.

Have anyone experienced this?



Banding at HPT11xx.pdf

[xerotec]

Re: Banding at HP T11xx

Look as starvation of gray or black color. Are you tray to print 2 copy of this at same time to see
what happens. Are the same copy

[vishop]

Re: Banding at HP T11xx

No, im only trying to print 1 copy. I print on the machine at site HP T1100 and in our office, HP T1120, both have the same kind of banding, taking place at exactly the same location.

[Kiran Otter]

Re: Banding at HP T11xx

I was going to say exactly what xerotec said; it's ink starvation.

Is the customer using genuine HP ink cartridges? Is your printer in the shop using them too?

Or you have air in the tube assembly. Which is easily caused by 3rd party inks, especially refillable ink cartridges.

You can try priming the tubes with something like this:

L607460 HP Designjet Ink Tube Air Bubble Removal Tool

Kiran

[Hewlett Slacker]

Re: Banding at HP T11xx

try a diffrent driver, thats usually the problem.

[vishop]

Re: Banding at HP T11xx

Hi Kiran,

When you guys said "ink starvation" do you mean that inks being supplied to the head has become less or none? If that it the case, shouldn't be the banding will start random and will become consistent until ink again has reached the head? And i printed different file/s on it, a full picture A1 size, no banding happened.

I print the same file for 3 copies, all bandings in the prints started in exactly the same location as i have previously attached.

The inks and printheads in the site and in our office are of the same source. I am in UAE and we are getting our supplies from US.

[vishop]

Re: Banding at HP T11xx

try a diffrent driver, thats usually the problem.

let me have a try on that.

[Kiran Otter]

Re: Banding at HP T11xx

If it's the driver, I'll eat my hat. But stranger things have happened.

And yes, I'm suggesting a printhead is running dry. And unless another image uses as much of that particular color as the one you're having a problem with, you may not see the problem occur.

And if you printed 3 copies, and did NOT get banding on the entire 2nd and 3rd copy, then I'm likely wrong about the starvation.

What happens if you flip the print 180 degrees and print it? Or print it turned 90 degrees, for that matter? I'm just curious.

What happens if you reduce it to half or quarter of the original size?

If I can get a response from HP I'll let you know what they say.

Kiran

[Kiran Otter]

Re: Banding at HP T11xx

Another thing that came to mind.. though it would be a fluke if both printers had the same problem, would be to check the bongo pumps/lifters that push up into the ink cartridges. Make sure they are all free and move up and down when the printer is initialized.

Kiran

[fixthecopier]

Re: Banding at HP T11xx

This may be off the wall, but a few months ago I had a Z series plotter that had an odd defect. Looked like it was "firing" one of the heads, causing it to "stamp" two lines of ink, sporadically in one area of each print. After trying everything basic, just before ordering a new carriage, customer informed me it started shortly after doing a firmware update. He was able to reload the previous level firmware and it stopped. Nobody who repairs plotters had heard of such a thing, but it worked. I went by today while I was in the building and it is still running fine. Firmware does some crazy things. just a thought, firmware is free.

[theengel]

[Kiran Otter]

Re: Banding at HP T11xx

This is gist of the reply from HP:

It looks like ink starvation. Try roating the print 90 or 180 degrees, see if it does the same thing. If the media is set to Plain or Bright White, change it to Coated. If it's a PS model, try printing through the web interface.

If you can get me the actual file, my contact at HP offered to try printing it to see if they get the same results.

Kiran

[vishop]

Re: Banding at HP T11xx

Hi,

1. It is not on the driver.

2. Previous firmware and current firmware - still same results.

I checked the machine base on the doubt that this may be due to ink starvation. I looked for a file that is the same or almost same amount of color as my test file is. There it is, banding happens a quarter part after starting the print. Rotate the file 90deg, same thing happen. Banding starts to happen not on the beginning but somewhere near the center.

I tried to print in A2 (before always in A1), same thing happens. I printed using black and white, banding happened in the center, then went OK again on the later part.

Printed landscape and portrait, same banding happens but different patterns. The weird part for me is, when i print the same file or orientation twice, the pattern of the banding is almost exactly the same.

KIRAN, where is this bongo pumps/filter you're talking about, how to check them?

And i am looking on a starvation on the gray ink?

[vishop]

Re: Banding at HP T11xx

i have attached a sample file in the beginning of the post

[vishop]

Re: Banding at HP T11xx

Scans.jpg


The one on top is from our shop, the one below is from our client, both banding is happening, it means that both of them are having the same problem?