New Refurb MP780 - 3eBK doesn't print at all.

[Maureen23669]

Purchased newly refurbished MP780. The 3e test grid does not print at all. Nor does the 3e print on regular docs. Tried 3 different print heads, including the new one sent with the refurb. New pigment cartridge. All other colors print perfectly.

When I replace the print head each time, I get the prompt for "auto print head align", but it fails every time. This has always happened with my MP780s, but hasn't affected the printing.

Each time I remove the printhead, there's a bubble of black pigment on that screen, but no bubble of ink on the others. Same with all 3 print heads. Tried cleaning heads with rubbing alcohol and windex ammonia. Have not cleaned new head at all.

 

[ghwellsjr]

This could be one of two problems:

1) It could be an electrical problem in your printer in which case you will not be able to fix it, but if you tell your printer that you are printing on matte paper, you will at least be able to print with the thin photo black cartridge.

2) Or it could be a clog in the purge line for the black pigment 3e ink in which case you will be able to fix it. So let's hope it's the later. Here's the process:

Open your printer cover.
Remove the 3e cartridge.
Using a syringe, eye dropper or straw, place a couple drops of Windex on the screen.
Use a flashlight to identify the black pads off to the right where the print head parks. There is a larger square one that is easily visible for the smaller dye ink cartridges. The one for the pigment black is to the left of that and you will only be able to see the right hand portion of it. Flood it with Windex.
Put the 3e cartridge back in the printer and close the cover.
From your printer, go to the printer maintenance and do a regular cleaning on just the black 3e group.
Do a nozzle check.
Repeat all these steps until all the nozzles are cleared.
If you get tired of doing this, leave Windex on the screen and pad, shut off the printer and let it sit over night or until the next time you want to try again. Many times, just having Windex sitting on the purge pad will slowly dissolve the clog in the tube.

It is also possible that the tube attached to the bottom of the purge pad has become disconnected but I really doubt it. I maintain several of these printers and none of them have ever had that problem. If that is the problem, it would be a big hassle to fix. Is it possible for you to return or exchange this refurbed printer?

Since you have other MP780 printers, you could take one of the heads from a working printer immediately after printing black with it and put it in the non-working printer and see if any of the nozzles will print. If they do, then you know it's not an electrical problem in the printer. However, you should be warned that some electrical problems in a printer can burn out any print head that is put in the printer in such a way that it can also burn out the electronics in any other printer you put the print head in. I would only recommend this if you have already swapped print heads and know that the problem is not propagating to your other printers.

One last warning: be very careful when removing print heads from your printers. You don't want to get any residual ink from getting on the electronics inside the head. This can happen if you shake the print head or drop it or even leave it laying on its side.

Good luck and let us know what happerns.

 

[bebeth]

I have also been having problems with my canon mp780 - took a while to find your thread and to realize that my problem was the 3e cartridge. Followed your instruction with the windex - several times - each time with a small improvement until IT WORKS!!! I used a Qtip dipped in windex to clean off what looks like the "brushes" that clean the print head - that seemed to help alot. THANK YOU SO MUCH!!

 

[leo8088]

It is possible that the purge unit is too dry. The purge unit relies on a small amount of vacuum to suck ink from the ink cartridge. If the purge unit is too dry there may be an air leak. You can use a syringe to drop a few drops of water onto the purge pad then close the lid and do another cleaning cycle to the BCI-3eBK channel. I had the exact same problem when I installed a new MP780 print head. I nearly panicked. I realized that my MP780 was in storage long enough to have the purge unit dried up.

 

[ghwellsjr]

I have also been having problems with my canon mp780 - took a while to find your thread and to realize that my problem was the 3e cartridge. Followed your instruction with the windex - several times - each time with a small improvement until IT WORKS!!! I used a Qtip dipped in windex to clean off what looks like the "brushes" that clean the print head - that seemed to help alot. THANK YOU SO MUCH!!

You're welcome.

Since I posted this answer, I have learned something new. As leo8088 pointed out, the purge unit can dry out, in fact, it can just not work anymore and the way to find out is to put some Windex or water on both pads, make sure it remains there for a minute as long as you don't do anything more, then close the cover to the printer and after the noise stops, open the cover again. If the liquid has been sucked away from both pads, you know the purge units are working and you can continue with the instructions above.

In your case, you didn't have clogged purge units because they eventually got the nozzles working again, but I'm posting this for someone else who might happen across this thread just like you did.

Just in case someone does have a clogged purge unit, you can repeat the process of closing and opening the cover several times a day and hope that eventually the liquid will get sucked down the pads. There is no point in wasting ink by doing cleaning cycles if a purge unit is not working.