PIXMA MP780 purge unit

[InkMon]

Trigger 37 I could use some of your expertise to help with my monitor, I do not have a Canon and rely on comments from those who do. I have made considerable changes and gradually getting it to record ok. A way to go yet though.

Terry

 

[stuber]

Tigger 37... Let me recap. I got the printer with a print head and all five cartridges in. Original problem was PUT IN CARTRIDGE. This problem was resolved by purchasing a brand new Canon Print head. Now with the brand new printhead and the original cartridges the nozzle check prints everything but the BCI-3e piece at the top. I have swapped out the BCI-3e with a brand new one. Same problem. This weekend I took my printhead and all five cartridges and put them into the MP780 belonging to a friend. I got the same indications. No BCI-3e printing. Is it possible that I got a bad print head? What else can I try?

 

[ghwellsjr]

If you remove the printhead from an MP780 it will display PUT IN CARTRIDGE but it means "put in printhead". If you put in the printhead with one or more ink cartridges missing, it will think they are all there--it has no way of knowing that any are missing.

When you first got this used printer, if the printhead was installed correctly, and it reported PUT IN CARTRIDGE, then it must either have been a defective printhead or it could have been bad electronics in the printer that made it think the printhead was missing. But since the replacement printhead does not produce the error message, that second possibility can be ruled out.

Now you have a situation where a brand new printhead in a printer of unknown history will not print anything with the BCI-3eBK (pigment black) cartridge. You did a good test by trying the printhead in another printer that was known (presumably) to work correctly. You could try some more tests if your friend will let you: Use his five known working cartridges with your printhead in his printer and use your five cartridges with his printhead in his printer. Make sure you turn the printer off and on after each new configuration so that it will do a clean/purge cycle and do enough printing so that you are sure that residual ink in the printhead will get used during the course of a test, otherwise you could get a false indication. You want to narrow down the problem to one item which could be the printer, the printhead, or the cartridge.

There are several possibilities that could keep the BCI-3eBK ink from printing:
1) An electrical problem in the print head--this could be ruled out by putting your friend's printhead in your printer--but take caution because....
2) An electrical problem in the printer that burns out the BCI-3eBK nozzles--you may discover after putting your friend's printhead in your printer that this was the case!
3) A nonfunctional purge unit that won't get ink starting to flow through the head. Putting your friend's printhead and cartridges in your printer might allow it to work if it had been primed in your friend's printer, so you need to run more tests. If this is the problem, then your printhead in your friend's printer should work. Maybe the reason it didn't was that you didn't give it enough purge cycles.
4) Something wrong with the cartridge. If you didn't remove the tape over the air vent (on both BCI-3eBK cartridges that you have tried), then this would prevent ink flow. Using your friend's would rule out any problem associated with a bad cartridge. You can also try blowing against the air vent to see if ink comes out the port on the bottom.

There are probably other issues that could account for this problem but you should get to the point where you can build a good case if it is determined that the new printhead was defective from the beginning. If your supplier is willing to swap it out for you, I would try it first in your friend's printer with his cartridges and if it works then try it or his original printhead in your printer with his cartridges.

Good luck.

 

[ocular]

Either blocked black of printhead (unlikely as this is new) or more likely a blocked purge line. Do Triggers 37 trick and drop some windex on the rubber boots that the head parks under. There are two of them. Turn the machine off and on to cycle the purge unit and then look and compare the rubber boots. If the pad is still moist then the windex is not sucked away and the purge line is blocked.

Also check the face of the black segment on the printhead and make sure it hasn't been mechanically damaged. Have seen some foreign object drop in the printer mechanism and quickly destroy a new printhead.

 

[talstails]

Hi,

I hope you don't mind me posting a reply here.

I have been having a similar problem for months now.

My big black ink cartridge from my MP780 will not print. Tried all those nozzle checks and deep cleaning.. didn't improve it at all. I get a big blank area where the big black cartridge is supposed to print in the nozzle check. I think I also get a message relating to Auto Aligned Failed or something like that when I try and align the print heads using that button.

I rang up Canon and they told me to take it to a service place but it will cost a fortune to get them to fix it and doesn't seem worth it. Is there a way of fixing it myself please? I've read about putting the print head in hot water and also stuff about the purge unit. I know where the print head case thing is but I'm not sure about the purge unit. I've also heard stuff about metho evaporating liquid. It has worked well before with waterlogged mobile phones haha.

Any help would be greatly appreciated.

Thanks in advance!

 

[gphj68]

Help. Symptoms - Partial printing of black text...colors all print fine. No flashing lights. MPX780 purchased in mid 2005. Reading these posts seem to be an area that makes sense for my problem. I have a .pdf of the scanned print test pages. Basically I get 2 clean lines of text, a partial line a skipped line and the pattern repeats. Any experts have an idea of where to troubleshoot? I have executed all software test/alignment programs available.

 

[Trigger 37]

Stuber,.. a lot has happened to me in the last several months, including Gastro-internal blockage, Pnemonia, and finally several weeks ago to get a 5th Stent put into my Heart. I'm in great shape now but I had a 95 % blockage in the primary artery to my heart. I was good as new once I got the new Stent. You have to love our new Medical Technology.

Anyway, you have not posted any new information about your problem since back in late May. So what was the final out come. After reading all the posts over and over, I'm think as others have said that it looks like you got a bad head or a contaminated contact on the back of the head. Since you got the same results in 2 different printers, I don't think you could blaim the purge unit in both, especially since his own head worked in his printer.

An other possibiity is you carried the same in carts. When you installed them in his printer, you should have done a couple of deep cleaning cycles to get your head "Primmed" with black ink. If that didn't work, you should have tried his ink carts. If you had a bad ink cart, it would not allow ink to be sucked into the printhead, and as a result it wouldn't print in any printer.

I've learned a new trick on testing heads that won't print anything, and it seems to work for me. Get the printhead in the center position and use some windex to saturate the suction pad where the black ink cart sets. Close the cover and let it set for a few minutes and the printer will park the head and raise the pads after 55 seconds. ONce it does this, over the cover again and repeat the whole process. As soon as it is finished, use the print driver to force print a nozzle test. If it now prints black nozzle pattern, you have proved the head is electrically working. What you have been doing is causing diluted black ink + windex to "Wick" back up from the bottom into the nozzles. When any ink is in there and you try and print it will work if the head is electrically OK. The head could still be clogged, but at least you have proved that it is not "Electrically Dead". It is amazing what you can learn if you know the right steps to take and what to watch for on each step.

Since you had a new printhead, I don't believe it has any problem with it, but it could be. You may need to go back to your friends house and try many things there, especially deep cleaning with his or new ink carts.

 

[Trigger 37]

gphj68,... Sounds like you have a simple partially clogged black printhead. Try these fixes one at a time (if you haven't already fixe the problem by now).

1. Run several deep cleaning cycles on "Black". After each cleaning cycle print only a nozzle check and examine it very closely. If you see good improvement, continue the cleaning unit the head is clean. If you don't see good improvement after 2-3 cleanings, go to step -2.
2. Open the cover and when the Printhead comes to the center unplug the power cord. Now you can remove and seal each ink cart (Masking tape works fine). Remove the printhead and go to the laundry room sink. Turn the faucet on medium hot with max pressure. Flush all the ink out of the top ports and then turn the head over and flush the bottom. Let the water stream focus on the black ink nozzle pattern. Move the head away from the water and turn the head over. You should see black ink puddle on top of the stainless steel filter screen. This is telling you that you got water to flow backwards through the printhead. Put the water stream back on the bottom of the nozzles and keep this up until you don't see any more ink coming out of any color. Now get a saucer and place a folded paper towel on it that is wet with hot water. Set the printhead on the towel and let it soak for a couple of hours. From time to time move the printhead to see if there is a nozzle pattern of back ink still coming out. Set the head on a clean part of the towel and very carefully add some drops of hot water just to the black filter screen, just enough to cover the screen. Let it set an hour. Repeat until there is no more black ink coming out.

Once you have it as clean as you can get it, dry off all parts of the head with compressed air or with a hair dryer. You don't want to heat the head, just blow it dry, especially on the back circuit board where the eeprom is hidden. Once you know you have the head dry (if you have the time, let is set overnight) put in back in the printer. Now check the ink flow in each ink cart, especially the black. To do this fold a paper towel into 1/4 size and put it in your left had. Hold the black ink cart over the towel and gently blow with your mouth into the air intake at the top read of the ink cart. This should force some black ink drop to fall onto the towel. If you don't get any, blow a little harder. When get the ink to flow, install all ink carts, plug in the power and run the deep cleaning cycle a couple of time to "Prime" the printhead with ink. Now run the nozzle check. It should be fixed by now, but if it isn't,... well item 3 will have to wait for another day.

 

[yupkime]

I received a MP750 today that had no output at all.
Parts were moving ok but no ink was printing on the paper.
Print head was almost new and inks were oem cartridges.
Deep cleanings didn't help at all.

As recommended, got some windex with ammonia and soaked the two purge pads on the right side of the printer and then did a power cycle.
Repeated this about 5 times, each time filling the pads with windex until almost overflowing.

Waited for a few minutes in between windex soakings
Tried a nozzle check and printed a test sheet and voila, perfect output.

Hard to believe but worked great.
I guess somehow the purge unit gets clogged or something and the windex trick worked great.

If it doesn't work right away, I would suggest you to be patient.
Better than opening it up for sure.

 

[mjaytee]

I received a MP750 today that had no output at all.
Parts were moving ok but no ink was printing on the paper.
Print head was almost new and inks were oem cartridges.
Deep cleanings didn't help at all.

As recommended, got some windex with ammonia and soaked the two purge pads on the right side of the printer and then did a power cycle.
Repeated this about 5 times, each time filling the pads with windex until almost overflowing.

Waited for a few minutes in between windex soakings
Tried a nozzle check and printed a test sheet and voila, perfect output.

Hard to believe but worked great.
I guess somehow the purge unit gets clogged or something and the windex trick worked great.

If it doesn't work right away, I would suggest you to be patient.
Better than opening it up for sure.

I'm here to vouch that this worked like a charm on my MP780. For obvious reasons I am trying my best not to "upgrade" my Canon. The 3e and 6e cartridges are worth their weight in gold. Yes, I know the newer cartridges are doable but I have a groove I do not want to disturb going for 5+ years with these vintage Canon cartridges. Thanks guys for taking the time to help us lost souls.