Why does the ink turn dark?

[PenguinLust]

Is old ink supposed to turn dark? The yellow cartridge is the same one that's been in there for God-knows how many years. I assumed that's the reason the yellow is so dark. But the cyan is weird. A couple of days ago I was printing some colour images, and the cyan was bright and beautiful. Then suddenly, today I was printing the same images, and the cyan is now all dark and flat. Why is that?
I Googled 'inkjet "ink turns dark"' and various other things, and got very few hits, and none of them indicate that this is a likely property of old ink. The printer manual doesn't discuss this either. So now I have to ask why my yellow is dark, and why my cyan turned dark overnight.
I have a Canon i860 running WinXPSP3.

 

[Grandad35]

Use the search feature and search for "cross AND contamination" (without the quotes) and select "Topic subject only" in the "Search in" box. You'll find several threads dealing with this.

 

[PenguinLust]

Ah, so this is all about cross contamination, is it? I see this affects a lot of Canons. Does this mean we should never buy Canon again?
I see a lot of information and suggestions in these forums, much of which seems apocryphal, and it looks like a lot of work to try everything. Let's start with something simple: how can I prevent this? I spoke to the previous owner who tells me he's never had this problem w/this, or any other Canon he's had. This could be because he uses his printers a lot, and I only do very sporadically, but there could be other causes.
It's probably too late to save the cartridges I have now, since the yellow one has green in that rear compartment. Thanks for your help so far.

 

[PeterBJ]

A common cause for cross contamination is one or more cartridges leaking. So what brand of cartridges are you using ? I have had similar problems with a cyan after-market cartridge leaking. The yellow turned green and the magenta a dark colour. Leakage and other problems are seldom seen with Canon original cartridges, so if you want to refill, use only Canon OEM cartridges.

If you want to refill, I recommend the "German" or "Durchstich" method. Here are excellent instructions: http://www.nifty-stuff.com/forum/viewtopic.php?id=2465&p=1

Another refill method is top filling. It may be easier than German method, but the drawback is that if the top fill hole is not sealed properly, the cartridge is sure to leak, even if it is Canon OEM. Do your cartridges have any screws or rubber plugs attached to the top (label) side ? If so, they have been top filled and you have a possible cause of leaking.

If the cartridges are Canon OEM they can be flushed and refilled. If they are not, you should throw them away and get some used OEM BCI 3/6 for refilling. If you only print a little then I recommend buying and using new Canon OEM's even if they are expensive. You may be lucky and find some after market cartridges that work well, but many Canon print heads have been ruined by using after market cartridges.

For comparison I've scanned and uploaded some Canon OEM cartridges, link here: http://www.nifty-stuff.com/forum/uploads/6881_bci_3_6_oem.jpg

In my opinion the problems are caused by the cartridges and not the printer, so it is not Canon's fault. I think this printer using non-chipped, easily refillable cartridges certainly is worth keeping.

So please post back with more information about the cartridges you are using.

Peter

 

[PenguinLust]

It might be a leaking problem, but I don't think it's an after market problem. This is a cartridge like the one I'm using:

I think it's OEM, but I haven't been able to get anyone to say. I've taken up the issue of short-term solutions elsewhere.

 

[ghwellsjr]

Yes, that is an OEM cartridge. I think your problem is letting the printer sit idle for so long, as you say, printing "very sporadically". I would recommend that you do a nozzle check once a week to keep the nozzles open and to let you discover as early as possible when a problem develops.

 

[PeterBJ]

If the cartridges are all Canon OEM, which have not been tampered with, that should rule them out as the cause of cross contamination.

But from your description of the discolouration it looks to me as if the BCI-6 BK is the culprit, as the yellow turned dark and the cyan turned dull.

My guess is that the cartridge may have been damaged or defective in manufacture, causing a small leakage of air into the ink chamber. Maybe the bonding of the top part to the rest of the cartridge was not perfect ? Maybe the suspected air leak is so small that problems only show up after the printer has been sitting idle for a long period ? I would not use that cartridge for refilling. The others can be refilled after a purging to remove the discoloured ink.

Hopefully your printer will be OK again with a new or refilled set of Canon OEM cartridges.

If changing the BCI-6 BK doesn't stop the cross contamination then I am out of ideas.

Peter.

 

[ghwellsjr]

If a cartridge has an air leak into the reservoir, then all the ink will leak out of it in just a day or two. If it isn't empty even after many months, then it can't have an air leak in the cartridge.

Sometimes, for who knows what reason, cross contamination can occur and after replacing the contaminated cartridge (which cannot be the culprit), and doing a head cleaning, the problem goes away, never to return.

If it does return, the problem could also be a leak in the seals inside the print head which is not generally repairable. Or the problem could be a purge system that is not working. To find out if this is the case, use a syringe, eye dropper or a bent straw to deposit some Windex or other window cleaner or just plain water on the two purge pads off to the right where the print head parks and make sure the liquid does not immediately drain away then do a cleaning cycle and see if it has now been sucked away. It will look shiny with the liquid on the surface of the purge pad and dull black with the liquid sucked away.

 

[PenguinLust]

If it does return, the problem could also be a leak in the seals inside the print head which is not generally repairable. Or the problem could be a purge system that is not working. To find out if this is the case, use a syringe, eye dropper or a bent straw to deposit some Windex or other window cleaner or just plain water on the two purge pads off to the right where the print head parks and make sure the liquid does not immediately drain away then do a cleaning cycle and see if it has now been sucked away. It will look shiny with the liquid on the surface of the purge pad and dull black with the liquid sucked away.

You think the purge system might not be working? Is that the same thing as the cleaning/deep cleaning? Because this device has done a lot of sitting around on the shelf I've had to make extensive use of the purge system, and it seems to be successful (although, when I first got it, I had to deep clean it several times to get it to work again). At least, it started printing properly after a fair number of cleanings.

It seems that the liquid was sucked away. What does that mean? I've photographed the various stages.

Unfortunately, I took a lot of pics, and didn't record exactly at what stages they were taken, so I'm just going by the time stamps:
This one was code marked for 18:24. It was taken before I dropped the plain water onto them:

I take it that those are the purge pads you were talking about?

And now with the water, code marked 18:27:

And then the last one, after the software cleaning, just before 18:29:

FWIW, I do have some other pics that are wet followed by others that are dry. While I was doing this, the printer started doing what it always does after it has idled with the power on for a while: buzzing servos. The print head assembly also started moving from left to right (thank God I didn't have my hand in there at the time!). I believe that mere buzzing of the servos may have also sucked away the water.

 

[ghwellsjr]

Yes, you have everything right. The best pictures of the purge system in action, too. I'm going to reference this post when explaining the purge system to other from now on.

Let's hope that doing weekly nozzle checks will prevent the contamination problem from occuring again.