Problem w/bizarre intermitten cross contamination (I think)

[PenguinLust]

Ok, something's in a big mess here. The other day I was here bragging that I'd some new data about cross contamination, (a quick recap: I have a Canon i860 and I cleaned out a thoroughly contaminated yellow cartridge and refilled it using the German method. My cartridges are all OEM and the only ones that have been refilled are the yellow and 6BK) but it's looking like it's not that simple. I printed another test pattern and the yellow was perfect, but the cyan and magenta had gone bad again. So I started printing these page-size test patterns to hopefully exorcise the contaminants. Here're the results:

Here's the first pattern. Repulsive, isn't it? You'll just have to take my word for it that the top is magenta and the bottom is cyan.

As you can see, it does seem to be exorcising the contaminants, so I thought 1 more page-size test pattern, and the following would be perfect.

Hah! Shows what I know. Yes, I started enumerating the order the patterns were done, but what you don't realize is that "4" is supposed to be black! So I started deep cleaning the 3eBK.
The colours don't look so bad at this resolution, but look at the inset, magnified to the definition that the original scan had: look at those horrible interlacing green lines!

This is the last one I did last night. I waited a while after doing the #5, so the contaminants had the opportunity to make some gains. The deep cleaning instantly, partially worked. Every time I got this streaking, I did another deep cleaning, but it never seemed to go away.

Seeing as these colours seemed to be contaminated by the yellow, I had the yellow removed overnight.

More than 24 hours later, I put the yellow back in, and tried again:

As you can see we are dealing with an incorrigible problem.

This was my last attempt.

I've got problems w/those lines, and I've just done a nozzle alignment, and cross contamination, a 3eBK nozzle that won't clean, and I just don't know what I should be doing.

I don't know if this is relevant, but when I analyze the cyan and magenta regions, I don't find that the RGB values are what I expect. For instance, even when the cyan is uniform and consistent, its red value is a good bit less than the blue and green, but it still seems to have significantly more blue. I don't know if that's the way it's supposed to be with ink jets, or the paper I'm using, or the scanner I'm using or what.

 

[emerald]

Your problem is most likely caused by a faulty print head and can't be fixed without replacing it. I'm purposely blunt because I've been there two times (post #25) and your printouts demonstrate classic symptoms: Do a head cleaning and then print out a fairly clean color chart. Wait a while, print the same chart and see strange colors and perhaps banding. Your printouts indicate interaction between the C, M and Y colors - the dye black could be involved too. The i860 has two blacks - a dye type and a pigment type. I think you indicated that the pigment black exhibits clogging.

Put your printer in the "Service Mode" and then request a print head pattern test. (service test print) If you're not familiar with the Service Mode, do a search on the forum. It's posted several places. This test is of little help in solving the cross-contamination problem but will show where the clogged nozzles are.

You are using the German method of refilling, which requires extra effort to flush a cartridge. If you've not already done so, flush and fill different Canon OEM CMY cartridges with fresh ink. Make sure the German refill hole is taped securely. Force a drop or two of ink to be expelled from each output by gently puffing on the factory vent while holding the cartridge over a sink. Then make sure it doesn't drip. The purpose is to prove the fault is not improperly sealed or improperly vented cartridges and/or stale, discolored ink. Do a head cleaning and print a clean color chart. Wait and print the same chart.

Next, to prove it's not excess ink "wicking" back up into the print head from the purge pads, do a head cleaning followed by printing a clean chart and then open the lid and let the head and cartridges set in the mid position for an hour. Pull the power cord so the head will not return to the purge position. The exposed head will NOT dry out within an hour. After a while, without doing a cleaning, print the same chart again. If the chart is now clear it does NOT prove that the purge pads are the CAUSE of the problem, only that they are possibly the SOURCE of the contamination. The theory goes that unexplained, unequal pressure between internal print head ink channels causes ink to migrate between adjacent nozzles while parked on a soaked purge pad. It's an anomaly that's a "stretch" for me.

It's also possible, and indeed likely, that the internal print head gasket between the plastic and ceramic sections has lost its seal between two or more color channels allowing for a slow bleed between them.

If any of the last two conditions exist. there's no reasonable fix. Taking apart the print head is a last ditch effort that ends in failure or damage at least 50% of the time.

The Canon iP4000 and i860 use the same print head if that's any help.

 

[tigerwan]

I second what Emerald said.

 

[mikling]

This is a failure mode of the printhead. One other source of cross contamination is when the nozzle plate delaminates from the ceramic substrate. The ceramic substrate is a series of troughs that hold ink. On top of that, the nozzle plate is glued to the ceramic. The plate covers the troughs and the glue seals them from each other. Over time, perhaps from repeated heat cycles or simply aging, the nozzle plate glue no longer seal the separate troughs of ink from each other....so the ink leaks across and you get the reported problem.

 

[mikling]

 

[emerald]

mikling: Thanks for sharing the very fine graphic and explanation. You have clearly added to our knowlege.

 

[PenguinLust]

Ok, I followed your directions and used this colour chart. Here're the results from that test pattern:

That's very different from the software test pattern. I believe that those squint graphs are supposed to indicate that the nozzles aren't clogged, which begs the question: how does one rationalize the bad black in my previous test patterns?

So, the first colour chart:

Please ignore the ghost images, I recycled some paper to do these tests. I find the results predictable against the image I used. The yellows look ok, but the blues are pretty dull and awful.

Then I did a head cleaning, and printed again:

This appears to be a vast improvement. I find this is little unexpected, since I didn't think the cleaning fixed this sort of problem, and before I printed vast amounts of raw cyan and magenta, but it stayed yucky-looking.

Just for kicks, I left the print head in the middle of the printer for an hour and then printed this:

and, of course, the colours are still excellent, for now. However, there were some disturbing ink splotches:

What's that all about?

 

[emerald]

The test pattern from the service mode is not as bright as it could be but it doesn't appear to have missing nozzles.

I can see a difference between your first test chart and the second and third. I'm guessing that the printer set for a while before printing the first chart which is the one with the contaminated colors. Your second and third chart confirm my suspicions that right after a cleaning or if the print head was not parked on a purge pad for a length of time, no contamination shows. . .which confirms my speculation that your print head has developed a bleed-over between at least two adjacent colors - dye black into magenta? I think the pigment black is OK judging by the service mode printout grid. It's probably a failure as described by mikling.

Mike, if you are around, what do you think?

I'm sending a test pattern that will give a more meaningful result. Let's see what it looks like.

 

[PenguinLust]

If you say so. I find the behavior of this printer very unpredictable with a new test pattern, and this one is no exception.

Now the cyan doesn't look so bad, but the magenta is an abomination! It's also pretty streaked. And look at that K! I'm used to the K looking pretty good on this printer, with the colours only being off.

Again, don't forget to neglect the test pattern on the other side of the paper, which you can see at the bottom.

 

[emerald]

Yeah, it looks like the magenta and dye black are indeed having an illicit affair. It's bad news - an internal failure within the print head.

The printer has had a fair amount of activity. The page count is 7,560 and the waste ink counter is at 47.5%.
This type of print head failure can occur anytime but is more likely to happen with printers with high usage.