Pixma MP 780 magenta and blue color won't print

[sgrisik]

I have a Canon Pixma 780 and have been very happy with it until now. The blue and magenta color has stopped working, black seems to be fine. I use LD ink cartridges. I have tried new ink cartridges, to clean the ink head (sorry I don't know the correct terminology) and done a cleaning and deep cleaning ALOT. Nothing has seemed to work. This week I put some drops water on the ink pads to the right where the ink cartridges rest. Looked as though the black absorbed but the color remained shiny. It is pretty mucky on those pads and around it but difficult to see the color pad so I can't be sure that the water didn't absorb. I use the printer a fair amount, a few times a week some weeks more than other. It never sits idle for more than week. Thanks.

 

[ghwellsjr]

Actually, the color purge pad is the one on the right and is easier to see. It is larger and almost square. The pigment black purge pad is the one to its left and is rectangular, although you might not be able to tell that unless you can figure out how to get a better look at it. Instead of looking from the center of the printer, look through the hole that the right-hand bracket fits in to raise the printer cover. You will need a flash light. You need to make sure the purge system is working before you attempt to clean the print head.

The best way to test your purge pads is to start by doing a nozzle check. Then put some window cleaner like Windex on the purge pads using a syringe, eye dropper, or pinched straw. Don't worry about over flow. Then just close the cover and wait until all the activity stops and reopen it. Look to see of both pads are clear of liquid. Let us know the result and then we'll provide the next step depending on the result.

By the way, you shouldn't do any printing except nozzle checks until you get this resolved and don't remove the print head or attempt to clean it until we give specific instructions.

Also, what country are you located in? You can put that info on your profile.

 

[sgrisik]

I am in the US, in Ohio. I put windex on both pads and they are both absorbing.

 

[ghwellsjr]

If you are getting absolutely no magenta and cyan from your nozzle check, then you probably have an electrical problem in your print head and you will probably need to purchase a new one.

However, to see if this is the case, you can remove all the cartridges from you print head and then remove your print head from the printer. Make sure you put the print head locking lever back down and unplug the printer. Take a paper towel and fold it in quarters and lay it on a counter top. Put small puddle of Windex on it and press the print head on it to blot up the ink. Keep doing this on a new section of paper towel/Windex until you can see the individual colors appearing as small lines. You want to see if cyan and magenta show up. If they do, you have an electrical problem and will need a new print head.

Don't get any ink, Windex or other liquid anywhere else on the print head. When you are done, return the print head and cartridges to the printer and do another nozzle check. If it asks you if you want to do an automatic alignment, hit the reset button.

Let us know what happens.

 

[sgrisik]

Yes, all the lines show up.

 

[ghwellsjr]

That's quite conclusive that you don't have a clog in your print head or anywhere else but instead the problem is an electrical problem that cannot be fixed except by putting in a new print head.

I would recommend buying one through a local authorized Canon service center for $50 plus tax. You can also find them on eBay.

You have one of the best printers around and you will not find a new one that is better.

However, I would check how full your waste ink tank is just in case you don't want to take your printer all apart in a short time to keep it running. Here is the process to see the percentage full it is and to reset it back to zero. You should not do step 6 where you reset it to zero, just leave it where it is. If the number is not much more than 50, you still have a lot of life left in your printer. If it is above 80, you're going to have to do something in the near future. Let us know what the number is.

 

[sgrisik]

the number is at 38. It looks as though a new print head will cost around $85 or so. I know this is a great printer but is it worth sinking almost $100 in to it when I can purchase a new one for a couple hundred? You have been very helpful, thank you.

 

[embguy]

sgrisik,
I agree with you not for not spending $85 for a new print head. But I would look for a good used one from Craigslist or Kijiji for $50 or less. Usually, people selling the used printer without ink. Any Joe-6-packs, who does not know the value of the printer, will not buy it because he has to spend $80 on ink after paying the printer for $50. They have the same reasoning as you have - Buy a new printer which is on sale. But they do not know the build quality of the new printer is not as good as the old one and has to wait for a while for a chip resetter.

For us, the refiller, we will be happy to take the printer with the empty OEM cartridges. I always take my time because I do not have any competitor for the printer. Wait for a mouth before making an offer. My offer may be the only offer during the month that was listed for sale. I purchased my MP610 for $12, my MP830 for $15 and my iP4500 for $15. At this price, why spend $80 for a new print head.

The MP830 had a clogged channel between the nozzles and the screen inlet. It took me over 3 months to figure it out. But I learned a lot during the process from people on this forum. Now, I can handle any clog as long as it is not electrical related.

BTW, your MP780 worth a few dollar on eBay. Make sure that you disclose everything!

 

[sgrisik]

You are a very helpful resource. I really don't understand half of what you're talking about (way over my head!) but I will look in to it. I will give it a few weeks and see what I can dig up and if I can't find something cheap enough I will sell it on ebay. It is not that old, I still have the box etc that it came in. Do you have the number for canon support? I would like to let them know this occured. Thank you so much. I hate to see an otherwise good machine that still prints b&w fine go in to a landfill!

 

[ghwellsjr]

the number is at 38. It looks as though a new print head will cost around $85 or so. I know this is a great printer but is it worth sinking almost $100 in to it when I can purchase a new one for a couple hundred? You have been very helpful, thank you.

$85?? Where did you get that price from? I found two eBay sellers for less than $60 including shipping (items 330362690496 and 350287345947).

The MP780 is going for between $50 and $100 in the Los Angeles area (craigslist) fully functional and sometimes with extra Canon OEM cartridges. It's even less with a bad print head. If you try to sell yours on eBay, the shipping will be $40 to $50. At least do yourself a favor if you decide to buy any other printer and keep your MP780 around for a while so that you can go back to it just in case you change your mind. You still have a lot of life left in it.