Help on my MX721 problem

[Celso]

Hello,

After a paper jam my MX721 started to present a very odd printing behavior. It is all about the cyan. It is like an ink starvation but the cartridge is full (and, as I mentioned, this problem started immediately after a paper jam that happened below the printing head).

I cleaned the head twice but the odd behavior is still present.

Ideas? Solutions?

Tks.

Below a picture of the "phenomenon". Also a nozzle check. Attached PDF files of scans made with the MX721 itself.

 

[The Hat]

Ideas? Solutions?

@Celso, congratulations you have described your own problem exactly, your Cyan cartridges needs purging and refilling, and please don’t print anything more till you can remedy this situation, you may also want to look at your refilling procedure again.

Ink starvation is a very serious problem and is mostly caused by not refilling immediately after the low ink warning appears, you gain nothing by waiting till the cartridge is empty, except ink starvation or possible nozzle failure, incorrect refilling is also another cause...

 

[PeterBJ]

I agree with @The Hat . It also looks like a cartridge problem to me. I think it is a coincidence that the problem started after a paper jam.

@Celso Are your cartridges 3rd party refillable cartridges? I have had a similar problem when testing a set of PGI-550/CLI-551 refillable cartridges in an MG5550. I think this nozzle check looks similar to yours:

The problem was caused by the sponge that had been shifted upwards in the cartridge, so it no longer contacted the ink inlet in the print head. The cartridges have vent holes above the sponge at around 3mm or 1/8" so I pushed the sponges of the cyan and magenta cartridges pack in place with a Q-tip without the cotton inserted in the vent holes. This solved the problem and after a cleaning of the nozzles I had this nozzle check:

Here and here is more about ink starvation with refillable PGI-x50/CLI-x51 and PGI-x70/CLI-x71 cartridges. If you are using Canon OEM cartridges then the best test tool is a new OEM cartridge, even if it is expensive.

 

[Celso]

First of all, thanks for your help.

Based on the posts above and your directions I tried very hard to fix the printer. I had no luck.

I use refillable carts. I also had with me Canon cartridges and two new refillable from different makes. I tried all of them (and used a lot of ink) several times but they did not work.

I am completed puzzled and frustrated after spending several hours in order to make the cyan prints work.

If I put some drops on the "top of the head of the tube" that makes contact with the cartridges, it "sucks" the ink (up to a certain point) and I am able to print a nozzle check (not perfect), otherwise there is no cyan on the nozzle check print. It seems that the printhead cannot suck ink from the cartridge or the contact between the foam of the cartridge and the "top of the head of the tube'" is not enough to allow the ink flow. Very odd behavior.

Ideas? Below a nozzle check print, which is very similar to the first one posted by Peter BJ above.

Once again, thanks.

 

[PeterBJ]

.....If I put some drops on the "top of the head of the tube" that makes contact with the cartridges, it "sucks" the ink (up to a certain point) and I am able to print a nozzle check (not perfect), otherwise there is no cyan on the nozzle check print. It seems that the printhead cannot suck ink from the cartridge or the contact between the foam of the cartridge and the "top of the head of the tube'" is not enough to allow the ink flow. Very odd behavior.....

I think you are right. The problem is most likely caused by a bad sponge to ink inlet contact. This could be caused by a sponge that has been shifted upwards in a refilllable cartridge or the rubber gasket could be dirty with old ink so it doesn't seal properly. The gasket also must be able to compress and expand freely, it must not be stuck in old dried ink. If the problem is also present with a new Canon OEM cyan cartridge, I think the rubber gasket is at fault.

If you don't know how to remove the print head for inspecting and probably cleaning the gaskets, then see this post by mikling.

 

[Celso]

Thank you.

I removed the printhead some few times at the time that I was trying to make the cyan work. I also removed and cleaned the gasket (which was not too dirty). I also printed with and without the gasket but it did not work as well.

What I have in my mind now is to pull part of the foam out of the cartridge in order to secure a good contact with the inlet. I will use pliers for that purpose.

I know that it seems a bad idea but I am out of good ones...

What do you think about it?

 

[PeterBJ]

If you mean to pull the sponge back in place I think the idea is OK. Use a small set of pliers and be gentle and careful not to damage the sponge.Do not remove part of the sponge.

My refillable cartridges have a large vent hole of almost 3mm or 1/8" diameter, so I used a Q-tip with the cotton cut away to push the sponge back in place:

Even if it is an expensive test, have you tried how the printer behaves with a new OEM cyan cartridge?

You could also test your cartridges for ink flow problems. Hold the cartridge over a sink or hold some kitchen paper/paper towel under the ink outlet. By blowing gently into the vent it should be easy to expel a drop of ink from the cartridge. Compare the cyan cartridge to one that works well for instance the yellow or photo black.

 

[Celso]

I tried with other cartridges and the behavior was the same. I cannot figure out what is happening. Somehow either the inlet is not able to suck the ink from the foam or it is not adequately touching it. I will try to eliminate the second guess with the pliers. If it does not work it means that I have a printhead with a very unique problem and I will have to buy another printer, as it is cheaper than buying solely the printhead...

I tried to push the foam from the top of the cartridge using a paper clip. However, I did not succeed on moving the foam into the ink outlet. I pushed very hard but it started to mess all foam inside of the cartridge.

 

[PeterBJ]

Have you tried a new genuine Canon cartridge? Have you tried to blow into the vent on the cyan and yellow cartridge to expel a drop of ink and compare the two cartridges?

I still think it is a cartridge problem, not a print head problem. If the cartridges are the cause of the problems and you continue to use the same type with a new printer I think you will get the same problem with the new printer.

Another cause of ink starvation could be that the sponge is packed too tightly against the wall dividing the ink and sponge compartments, blocking the opening at the bottom of the divider. See this video from Precision Colors.