Canon MP540 - Strange magenta inkflow problem

[ThrillaMozilla]

This air-channel breaks the flow of ink from the spongeless side and results in ink starvation. While I have cartridges with this air channel that work fine, I did experience ink starvation once that may have been due to the air-lock.

Think of the air channel as a bubble. You can remove a bubble by tapping the cartridge. Remember that air bubbles rise. If that one bubble is followed immediately by a bunch of other bubbles, then you know that ink was not flowing into the sponge.

I try to remember to tap it to remove the bubble just before I install the cartridge in the printer.

It's interesting that you have had cartridges that worked even with a bubble stuck there.

 

[stratman]

Think of the air channel as a bubble. You can remove a bubble by tapping the cartridge. Remember that air bubbles rise. If that one bubble is followed immediately by a bunch of other bubbles, then you know that ink was not flowing into the sponge.

I try to remember to tap it to remove the bubble just before I install the cartridge in the printer.

Will try that next time I see an air bubble.

 

[ThrillaMozilla]

I'll be curious to hear about it. Most of my cartridges are opaque, so I'm in the dark about what goes wrong (and thinking/hoping all the problems are in the past, anyway.

 

[PeterBJ]

Thank you guys for all your suggestions, they helped me solve the problem

I succeeded in recreating the error. Printing 5 A4 B/W test photos didn't make the magenta cartridge fail, but a magenta purge page created in MS Word with a large rectangle with magenta fill color, RGB values 255-0-255 did the trick. The first page printed OK, the second produced this result, the first picture is reduced in size, the second cropped, click to enlarge:

and a cropped image:

After the cartridge had failed I examined it and found that the outlet sponge and the encircled area were a lighter color than normal. Here is a scan of the failed cartridge and a normal one, click to enlarge :



The failed cartridge still held about 4mm or 5/32" of ink in the reservoir. I left it in a cartridge clip overnight, and checked it in the morning. It had not changed in appearance. I put it back in the cartridge clip for protection and tapped it hard against my desk, both with the ink outlet and the chip facing down. Suddenly the ink in the reservoir disappeared into the sponge and the ink outlet and the encircled area turned into the normal darker color within a minute or less.

I must say stratman was perfectly right about the ink starvation and that my previous tests had not stressed the cartridge enough. Also ThrillaMozilla's suggestion to tap the cartridge worked perfectly. I don't think the vent was clogged. Holding the cartridge over the kitchen sink, after having tapped it, and blowing into the vent caused ink to exit from the outlet in a normal manner. I also think the sponges were in no need for reconditioning.

I think the cause of the problem was either that the sponges had been shifted in position by my poking with a needle or that I had failed to maintain pressure on the SquEasyFill bottle when withdrawing the needle, causing an air lock.

I'm glad the problem was a cartridge and not a clog in one of the tiny ink passages in the upper black part of the print head.

Re hard water and conditioning:
I also live in a hard water area, so I use demineralized water for flushing cartridges. When you use a Freedom Refill adapter, you can flush a dye ink cartridge completely with less than 200 ml of water. When bought in 5 liter quantities demineralized water is not very expensive, and I need not worry about lime deposits inside the cartridge. But I think you can flush with hard water till the cartridge is clean and finally flush with a little distilled/demineralized/deionised water. I think you will only get lime deposits inside the cartridge, if you leave the hard water in the cartridge and allows it to evaporate. Demineralized water will not dissolve lime deposits already in the cartridge, some acid like acetic acid will be needed. But maybe hard water is not that big problem, I have flushed cartridges with hard water without subsequent flushing with demineralized water without ill effects.

I don't know very much about contitioning of sponges. That is something I need to learn more about. But I think sponges should not be completely dried after flushing. If too dry, they may be hard to wet with ink. Compare a completely dry rag with a slightly moist rag. The dry rag is hard to wet, the moist rag absorbs water readily.

Re German method vs Topfill method:
Even if I have refilled 50+ cartridges with no problems using the German method, this incident has made me consider changing to the the Topfill method. With the topfill method you don't risk dislocating the sponges, although I use sharp needles to reduce that risk. My primary reason for preferring the German method is that you need not tamper with Canons sealing of the cartridge if you purge using a Freedom Refill adapter. But I think a low profile silicone plug plus aluminum tape make a secure seal. I had a CLI-521 C cartridge that had been purged after removing the plastic ball and sealed with a plug plus aluminum tape. I topfilled that cartridge pr miklings instructions and using a SquEasyFill bottle. It was actually easier than German refill and the weight after refill was also OK: 20.4 grammes. One more bonus: With topfill you can use blunt needles without problems. So I wonder if I should change my preferred refill method.

 

[ThrillaMozilla]

Nice work! Proof of an air lock. I'm going to bookmark this.

Next time, tap it with the reservoir up. That aims the bubble straight up, and you don't have to protect it with a clip.

We still don't know why and when this air lock developed. It's interesting that most of the ink was removed from the reservoir already before the problem occurred. It may be that the air lock was not there when the cartridge was installed, or if it was there, it didn't impede flow until the ink level got low.

I notice that OEM cartridges apparently rarely or never have this problem, and yet they surely can get air in that opening. Mikling tells us that the sponge must be in contact with the small opening between chambers, so maybe you're right, PeterBJ. Perhaps it does have something to do with sponge position.

 

[ThrillaMozilla]

PeterBJ, I think you just gave us an excellent diagnostic tool. If the exit port is light in color, that means that ink is not getting out of the cartridge. If it's dark in color, that probably means that the print head is clogged.

 

[The Hat]

PeterBJ, I think you just gave us an excellent diagnostic tool. If the exit port is light in color, that means that ink is not getting out of the cartridge. If it's dark in color, that probably means that the print head is clogged.

http://www.nifty-stuff.com/forum/uploads/thumbs/6881_inkflow_problem3.jpg

A very good point ThrillaMozilla but only if you have two the same cartridges to compare with.
It should also be noted that any loss of ink during printing is nearly always the cartridge thats at fault.

So it should be one of the first things to check rather than immediately assuming
the print head is the couplet and has a clog in it.

Another tip in you live in a hard water area is to add a dash of salt to your water before using
it to flushing out your cartridges then finish with a fill of some distilled water..

 

[PeterBJ]

After flushing and drying the cartridge, I have tried poking around in the sponge using a blunt needle, and watching what little can be can be seen of the sponges through the transparent end wall. The sponges appear to be firmly wedged in the cartridges, so they do not appear to shift position easily. That makes an air lock the most probable cause of the malfunction. I agree it is then the best thing to tap the cartridge with the ink reservoir facing up.

The Hat wrote:
It should also be noted that any loss of ink during printing is nearly always the cartridge thats at fault.

I also think clogged nozzles causes a regular banding pattern, not varying as the ink starvation caused.

 

[ThrillaMozilla]

I don't have any data on this, but I just wouldn't ever put tap water into a cartridge, especially pigment ink, which could flocculate and become impossible to remove.

For one thing, tap water has so many dissolved solids that could be deposited in the print head in response to drying. In particular, calcium salts precipitated from hard water can be quite hard to remove. Ammonia certainly isn't going to touch them.

 

[ThrillaMozilla]

The Hat wrote:
It should also be noted that any loss of ink during printing is nearly always the cartridge thats at fault.

I also think clogged nozzles causes a regular banding pattern, not varying as the ink starvation caused.

Yes, both good points.