Canon MP780 won't print color at all

[kcbaltz]

My Canon Pixma MP780 has been giving me fits this weekend. The problem started with the printer only printing in horizontal stripes. In other words, a 1/16" stripe of printing, then a simliar stripe blank, then a stripe of printing, and so on. I figured it was clogged and took the printhead out to clean it with some alcohol, which has worked in the past. This didn't help and when I put the cartridge back in a loaded the inks, it would no longer perform the auto-align. Also, I tried some color "priming" images (large blocks of solid color) and only about the first half of these would print before the color would fade out.

I finally tried the suggestion on this forum to soak overnight in windex. After doing this, then blowing out the cartridge with compressed air, the thing refused to print entirely. All the ink carts had been keep in a ziploc and when I took them out I dabbed them with a paper towel and the ink flowed freely. After running the cleaning cycle and taking the printhead out, I could dab it against a paper towel and see all the colors, so it seems to not be clogged. After a bit more fussing with alcohol on the print head, the big black printing has returned and seems to be working fine (it was not stripey to begin with. However, I can't get a drop of color to appear on any printouts.

Any suggestions? I've tried dropping quite a bit of alcohol into the purge unit and it seems to suck it up OK. I notice there's quite a lot of ink around it, not sure how messy it's supposed to be.

 

[embguy]

... Also, I tried some color "priming" images (large blocks of solid color) and only about the first half of these would print before the color would fade out.

By printing large blocks of color may have killed the color nozzles. When the printhead is clogged, printing large blocks of color will kill the printhead because there is not enough ink going through the printhead to cool it. Eventually, the printhead overheat... and die.

I finally tried the suggestion on this forum to soak overnight in windex. After doing this, then blowing out the cartridge with compressed air, the thing refused to print entirely. All the ink carts had been keep in a ziploc and when I took them out I dabbed them with a paper towel and the ink flowed freely. After running the cleaning cycle and taking the printhead out, I could dab it against a paper towel and see all the colors, so it seems to not be clogged. After a bit more fussing with alcohol on the print head, the big black printing has returned and seems to be working fine (it was not stripey to begin with. However, I can't get a drop of color to appear on any printouts.

By this time, the color nozzles are dead. No amount of soaking will make it work again.

Upload a nozzle check pattern. We will be able to determine it is a clog or hardware problem...

 

[kcbaltz]

This is the most successful nozzle check I've been able to get it to do since I posted my question initially.

The good news is it's printing color again. However it's not very much and it still has the horizontal blank stripes.

 

[ghwellsjr]

You definitely have some clogged nozzles, and some ink flow problems, and you may have an electrical problem in your dye ink nozzles, but let's hope for the best. I'm going to give you two links for people who have successfully gotten their printers working again. Please read these carefully and follow all the links embedded in these two threads until you understand my technique. Then give it a try and let us know how it works. Remember to be patient, it could take time.

http://www.nifty-stuff.com/forum/viewtopic.php?id=4246

http://www.nifty-stuff.com/forum/viewtopic.php?id=4252

 

[kcbaltz]

I ended up buying a new print head after trying all the solutions offered. That fixed the problem perfectly.

Some notes for anyone who reads this later:
1) Don't print the large blocks of color in an attempt to "prime" your cartridges. Apparently this can burn out the print head. The flowing of the ink keeps it cool, so make sure the ink is flowing via Nozzle Checks first.
2) Soaking in Windex didn't help
3) Flushing with warm water and then blowing out with compressed air didn't help
4) Flushing with alcohol didn't help.
5) There is a noise I associate with this printer that it makes when it is warming up. It's a high-pitched whine that sounds a bit like morse code and you you can hear it in between movements of the printhead. My failing printhead wasn't making this noise. The new head makes the noise as before.

In general, I've found alcohol good for clearing clogs in the past, but I may try Windex next time.

Also, the printhead was ~$60. It came with a recommendation that generic inks may have caused my printhead to go bad. This may be so, as I do use generics, but I did the math and the cost savings paid for the printhead after 9 cartridges. I've used quite a few more than that in the several years we've had this printer and the original printhead, so I will still be using generics.