i950 wont print cyan; yet it works using purging syringe. What to do?

[Lilla]

i950 wont print cyan, yet I can get a flow using a purging syringe.
What could cause this behavior? And can it be fixed?

I am trying to fix my sisters Canon i950 printer. It was working perfectly before she went on vacation. It now has the problems noted below.

i950 problems observed:
1. Nozzle check & extended nozzle check show nothing at all from Cyan channel.
2. When the cyan ink cartridge is removed, I observe that there is NO small puddle on ink pickup as there should be. Conclusion: Cyan ink is NOT being delivered to the ink pickup. This is confusing to me as I am able to get a flow through the cyan channel using a purging syringe.
3. When Media Type: plain paper is selected, then photo-cyan (in addition to cyan mentioned above) does *not* print. When matte paper (or anything other than plain paper) is selected, then photo-cyan prints.

Next I switch print heads...

All of the above problems go away when I switch to using a known good print head borrowed from my i960 printer (it uses same print head as i950). When doing the tests above on the i950 print head I used the same ink cartridges that I used to test the i960 print head in the i950 printer. I am using inkjetgoodies (IJG) bulk refill ink; genuine canon BCI-6 cartridges (3 sets) and IJG BCI-6 blank cartridges filled with IJG bulk refill ink (1 set).

Conclusion: The problem is in the i950 print head.

Ive cleaned the i950 print head using the procedures below 3 times and the problem remains unchanged. Im puzzled by this because I am able to get a good flow through the cyan channel using a purging syringe.

Print head cleaning procedures I used to clean the i950 print head
First, I cleaned the print head using a steam cleaning technique I read about years ago in another printer forum (dpreview.com I think it was). Steps: Fold a paper clean towel several times to make it thicker (I fold 3 times to make 6 thicknesses); wet the folded paper towel and squeeze out the excess water; place the wet paper towel on a clean glass plate and heat it in the microwave oven until it is hot (30 seconds is what I used). Remove the plate from the oven. Now blot the print head on the steaming hot paper towel. Dont rub the print head on the towel, just move it around on the hot paper towel using a blotting action. The steam will soften the ink and draw any excess ink out of the print head.
RESULTS: When I was done I examined the ink blots patterns left on the paper towel and was surprised to see nice uniform patterns of 6 colors, like I would expect to see from a good (not clogged) print head. I was surprised to see that each blot pattern, even the final ones, showed the same amount of ink for the cyan (that is not printing) as for the other colors.
Second, I cleaned the print head by forcing hot water through each ink port to see if I could get a nice even stream of water coming through each ink jet port. Results: Successful. Steps: I removed the print head, removed the little rubber pieces over the ink ports inside the print head. I flushed each of the 6 ink ports with hot water using a purging syringe (a syringe fitted with short piece of tubing). I did this until I was getting a fine even spray through each of the 6 ports. I used canned air to blow the water out of each of the six ink ports, and to dry the outside of the print head.
Third, I forced Windex (original formula with Ammonia D, as Ive seen recommended in this forum for this purpose) into print head ink jets using the purging syringe. Then I filled a small container with enough Windex to cover the print head ink inlets and let it sit over night. Next morning I flushed out the Windex with hot water. Then I used the canned air to clear out the water from the 6 ink channels in the print head, and also to remove any water on the outside.

---

What could cause this behavior?

Is there anything else I should try before I give up?

Thank you for your ideas and insights.
Lilla

 

[Lilla]

The problem I am having could be a wiring problem inside the print head... right?

Below is the post I came across that made me start thinking about this possibility.

Clogged Canon print head by Neil Slade (then scroll down to post #78)

5) I have dismantled a print head-- this is an extreme measure, and does not guarantee success, so only try this as a very last resort, ...snip.... YOu can also break the electronic ribbon connected to the nozzles- and this can not be repaired- so be EXTREMELY careful if you feel you need to do this.

Is it worthwhile to dismantle the print head, using instructions here, look for a problem with a wire (or solder point) and attempt to fix it? Has anyone ever done this before? or should I give up?

Thank you any advise and for sharing your experience with me.
Lilla

 

[panos]

"What could cause this behavior?"

Usually the cartridges. Try an original Canon cartridge and see if the problem persists.

 

[Grandad35]

This is a long shot, but also check that the soft rubber seal that seals the cyan cart to the printhead is still in place and clean. It is possible to blow these seals off with some of the more aggressive cleaning techniques (I've done it twice).

If it is an electrical problem in the head, it's finished. It is virtually impossible to find a broken connection with this construction, much less repair it.

 

[Tin Ho]

If the print head worked perfectly prior to your sister's vacation but not afterwards I would say it's not a problem of broken electronics. It's a clog caused by ink which has dried in the nozzles and in the ink feeding tube. Unless you have caused a damage to the electronics when you tried to clean the print head, a clogged print head in the worst case will print nothing.

If you have an empty ink cartridge on hand use it to make a cleaning cartridge. Purge the ink remaind in the sponge. Fill it with diluted Windex fluid. Plug it into the printer. Run one or two cleaning cycles to let the Windex fluid sucked into the print head. Pour some diluted Windex fluid onto the padding where the print head normall park when the power is off. Turn the printer power off and let the printer sit for a few hours. Run a cleaning cycle every hour and one more before unplug it and swap with a good woking ink cartridge. Do a nozzle check to see if it prints again and if ink flows at all.

Repeat the process a few more times until the clog is cleared. It's time consuming. But if there is a clog it will unclog eventually. This process will waste a lof of ink from the nozzles that are not clogged. Each time you do a cleaning cycle some good ink is lost. So you may want to use cheap bulk ink instead of OEM ink. I saved a print head from an ip6000D using this process. The print head had a very bad clogg with one missing PM and partially clogged yellow.

 

[Lilla]

"What could cause this behavior?"

Usually the cartridges. Try an original Canon cartridge and see if the problem persists.

Thank you, this is a good point. I have 3 sets of original Canon ink cartridges (refilled with IJG bulk refill ink) and one set of new IJG blanks (refilled with IJG bulk refill ink). By now I have tried them all any number of times. The set of carts I am using for testing purposes are ones I know to be good because they work fine when used in the i950 with the print head borrowed from the i960 printer. And, they work fine in the i960 printer with i960 print head.

Also, to assure each cart (esp. the cyan) is flowing properly before I use it, I blow some air into the vent over the sponge section into a paper towel held over the ink outlet, and check that some ink is coming through onto the towel.

Panos, your post make me recognize that I made a mistake in my original post, which I have now corrected in the original as follows...

Correction...
All of the above problems go away when I switch to using a known good print head borrowed from my i960 printer (it uses same print head as i950). When doing the tests above on the i950 print head I used the same ink cartridges that I used to test the i960 print head in the i950 printer. I am using inkjetgoodies (IJG) bulk refill ink; genuine canon BCI-6 cartridges (3 sets) and IJG BCI-6 blank cartridges filled with IJG bulk refill ink (1 set).

Error...
All of the above problems go away when I switch to using a known good print head borrowed from my i960 printer (uses same print head as i950) and using the same ink cartridges as used for i950 test above (wrongly stated, see above). I am using inkjetgoodies (IJG) bulk refill ink; genuine canon BCI-6 cartridges and IJG BCI-6 cartridges.

 

[Lilla]

This is a long shot, but also check that the soft rubber seal that seals the cyan cart to the printhead is still in place and clean. It is possible to blow these seals off with some of the more aggressive cleaning techniques (I've done it twice).

Thank you. It's good to consider the simplier things that can go wrong too. Yes, all six soft rubber seals are squeaky clean and in place, these seals are soft and subtle like they should be, not hardened or anything. I usually remove the soft rubber seals and clean them when I use the purging syringe. When I put the rubber seals back I put them back on in a random order, so the seal under the cyan has changed several times now, thus we know that the problem is not with a faulty soft rubber seal on cyan. One time I put the print head back in the printer and loaded the cartridges and did a nozzle check, before it dawned on me that I had forgotten to put the 6 soft rubber seals in the printhead. What surprised me is that the nozzle check looked OK, and there wasn't a mess inside the printer or anything, I got lucky on that goof I think.

I've been reading your post about how to make a hose to attach to the faucet so I can use hot water pressure to clean ink cartridges and printhead. I've also read where you use an air compressor. At this point I am using only a purging syringe (hand operated) and some canned air. Our air compressor is a big thing in the garage used for air stapler, air nail gun and such, I guess when you say you use an air compressor it is something smaller and more controllable, right?

If it is an electrical problem in the head, it's finished. It is virtually impossible to find a broken connection with this construction, much less repair it.

Thanks for that advise. I'll continue to try cleaning techniques in the off chance something will work yet...

 

[Lilla]

If the print head worked perfectly prior to your sister's vacation but not afterwards I would say it's not a problem of broken electronics. It's a clog caused by ink which has dried in the nozzles and in the ink feeding tube.

If you have an empty ink cartridge on hand use it to make a cleaning cartridge. Purge the ink remaind in the sponge. Fill it with diluted Windex fluid. Plug it into the printer. Run one or two cleaning cycles to let the Windex fluid sucked into the print head. Pour some diluted Windex fluid onto the padding where the print head normall park when the power is off. Turn the printer power off and let the printer sit for a few hours. Run a cleaning cycle every hour and one more before unplug it and swap with a good woking ink cartridge. Do a nozzle check to see if it prints again and if ink flows at all.

Repeat the process a few more times until the clog is cleared. It's time consuming. But if there is a clog it will unclog eventually.

Tin Ho, good idea. OK, I have a windex cleaning cartridge (made it some time ago actually) and I am in the process of trying your procedure. Actually I had used the windex cartridge some, but your procedure is more rigourous and I am willing to give it a try. Putting some windex on the parking area sounds like it might help.

The discouraging part is that through all of this I have never seen even the slightest trace of any cyan blue showing up in a nozzle check or extended nozzle check.

Lilla

 

[Grandad35]

...I guess when you say you use an air compressor it is something smaller and more controllable, right?

No, it's a 5 horsepower compressor with a 60 gallon tank that runs at 115 psi. It's easy to set the pressure regulator at a lower pressure for this type of use.

 

[Lilla]

...I guess when you say you use an air compressor it is something smaller and more controllable, right?

No, it's a 5 horsepower compressor with a 60 gallon tank that runs at 115 psi. It's easy to set the pressure regulator at a lower pressure for this type of use.

Grandad35, thanks. That's good to know. I'll have to learn how to use it then. We also have a house painting attachment that allows one to control the PSI, and it might be useful too. This is a little out of my comfort level so Ill have to pick a time that seems right for doing it.

Tin Ho, I tried it for awhile without any signs of improvement. I was uncomfortable with dumping so much ink with all of the cleanings. I think the windex drip technique below might be a more efficient way of delivering windex to one (or more) injet channels.

As my last effort I am trying the windex drip technique posted by Steph here scroll down to post #66.

Actually, I've modified Steph's procedure a little to fit my particular needs.

Every now and then I pull the drip tubes and do some cleaning with the purging syringe.
* push and pull water through the head a few times
* maybe use a little canned air

And then reattach the drip tubes and continue the windex drip technique.

Lilla