Canon Pixma MP640: Cyan not printing properly

[Jedzi]

I’ve got an 8 year old Canon Pixma MP640. It’s been pretty trouble free until it recently stopped printing the blue (cyan) properly.

I’ve changed the cartridge, done 2 or 3 nozzle cleans, a deep clean, a head alignment and I’ve taken the printhead out and washed it. The deep clean and washing the printhead seemed to work when I did the nozzle check, but after I’d printed 1 sheet it reverted to the problem.

Given the age of the printer, have I reached the end of the road with it, or is there anything else I can try?

Thanks,

Jedzi

 

[PeterBJ]

Please upload a scan of the nozzle check and possibly also a scan of a print showing the error. To get a good scan of the nozzle check with the MP640 see this post.

 

[Jedzi]

Hi there,

I had a good go at finding that Advanced Settings tab, referred to in the post you linked to, but I'm afraid I couldn't find it anywhere, so I took a photo of the nozzle check with my decent quality digital SLR.

The first photo shows what I got when I did a nozzle check this morning. The 2nd one, which is showing some blue, is more representative of what I've been getting.

I've been getting similarly variable results with actual output. The output I've attached should be of a rainbow against a blue sky. As you can see, there's no blue on it. Previously I've been getting some blue.

Thanks for your help with this.

Jedzi

 

[stratman]

Do you use new OEM Canon cartridges, new aftermarket cartridges, or refill one of these types of cartridges?

Magenta looks pink. Maybe it's lighting or artifact in making the JPG image. Maybe it is the ink itself if aftermarket. Crop your nozzle check images before posting if you can. Try scanning a nozzle check, crop and post. Maybe the quality will be better than those you posted.

Cyan has worked but is variable or disappears altogether. This sounds like classic ink starvation due to poor ink flow from the cartridge. You stated you tried a different cartridge. Refer to my first paragraph and let us know what that cartridge is as well. The fix for this is a new cartridge or flushing and refilling the cartridge if you refill.

DO NOT PRINT ANYTHING BUT NOZZLE CHECKS UNTIL ISSUE RESOLVED (or recommended by someone here)

 

[Jedzi]

Hi there,

It came out worse when I scanned it. I've retaken the two photos - the light's better now & I've cropped them, which might help.

I've also done a close-up of the nozzle check where it's printing some cyan.

Both cartridges are non-branded ones I bought on Amazon. I've been using similar ones for the last 8 years and they're generally well reviewed ... tho of course that doesn't mean they never go wrong.


Jedzi

 

[stratman]

Thank you for he improved images.

Both cartridges are non-branded ones I bought on Amazon.

Single use or refilled?

I tend to recommend a new OEM Canon cartridge for diagnosing. Others say a new aftermarket cartridge from a known good supplier is sufficient.

One thought: is there anything blocking the air vent on the outside of the cartridge? Also, is here any fluid blocking/filling the internal air channels inside the cartridge?

How long was it between the time the printer functioned appropriately and then did not? Was the change sudden or worsen over time?

 

[Jedzi]

OK, here's where I feel red faced. I opened up the printer to check the cartridge and noticed that the pull-off tab on the back / top of the cartridge was still partially left on, which was odd. When I took the cartridge out, in fact it hadn't been pulled off at all. I checked the other cartridge that my son had put in to see if that was the problem ... and it was exactly the same.

I've just spoken to him and he had forgotten that you have to pull it off. However, I really don't understand how I'd missed it.

This doesn't quite explain how some of the nozzle checks had shown no blue and some had shown some blue.

However I've just done a nozzle check and it was absolutely fine. I then re-printed the rainbow picture I posted above and it has a lovely blue background, so the problem seems to be solved.

Many thanks for your help. I wouldn't have found it unless you'd asked me to go back & check the cartridge.

Jedzi

 

[PeterBJ]

Thank you for the feed-back.

 

[stratman]

Congratulations on resolving the problem. Thanks for the feedback.

This doesn't quite explain how some of the nozzle checks had shown no blue and some had shown some blue.

It's physics in action. It is the result of dynamics of ink moving through the sponge under the negative pressure generated by the print head to suck the ink out of the cartridge. Ink flow through the sponge apparently is not precisely uniform across the sponge and results in the variable deposition of ink when the air vent is blocked. A sufficient amount of time between printing attempts may allow ink to seep into the ink exit port sponge and once again you have something on the printed page which may be variable in deposition. Under normal conditions any variation in ink flow through the sponge is insignificant.