mx850 don't print black, cleaned head, new carts, new head, whats next

[ghwellsjr]

First off, the part of the print head that is constantly wet is not the part we are concerned with here. We are concerned about all the other internal parts that get wet when the print head is put under flowing tap water or submerged in a cleaning solution.

Are you claiming that if I finish off with pure (distilled) water, then there is no risk to burning out a print head, even without drying the print head? I can just take a print head submerged in pure (distilled) water and put it immediately into a printer and it will not burn out?

Now, where do I find pure (distilled) water? The last time I looked for it, I could only find de-ionized water. Will that work?

 

[turbguy]

Actually, deionized/demineralized and filtered water it used in Large Electrical Generators to cool hollow copper windings. The conductivity of the water is so low, there is practically zero current flow from the water (in conductors energized to over 23 KiloVolts) to ground, so there's no problem. BUT... Why take a chance with your printhead? Let it dry...

 

[leo8088]

Are you claiming that if I finish off with pure (distilled) water, then there is no risk to burning out a print head, even without drying the print head? I can just take a print head submerged in pure (distilled) water and put it immediately into a printer and it will not burn out?

Yes absolutely. I have done that probably more than 30 times. The water was tap water. I never had a damaged print head caused by not drying the print head before installing it back to the printer. There are other reasons a print head may be damaged in the soaking operation.

 

[leo8088]

In case you haven't read my warnings before: after cleaning a print head, let it dry for two days in a warm spot before putting it back in your printer, otherwise you run the risk of permanently damaging both your print head and your printer as a result of liquid getting on the internal electronics when power is applied.

In my opinion you actually do not want to dry the print head so thoroughly before reinstalling it back to your printer. The following cleaning or deep cleaning cycle would be much less effective. If there was a clog and soaking did not dissolve the ink in solid state that was clogging the nozzles soaking might have soften the solid ink and a deep cleaning cycle might be able to suck it out. If you dry the print head so thoroughly the ink solid would be back to dry solid state again. Cleaning cycles would not be able to unclog it still. The whole purpose of soaking is defeated.

I have soaked a few print heads a few times over several days. An i560 print head was completely unclogged successfully. There is a 50/50 chance it won't work but what will you lose from a damaged print head than a clogged print head? I have heard that if you soak with Windex there is a very good chance the clog will be unclogged. It always takes more than a day of soaking.

 

[jackypunker]

Canon MX850 Originally started showing lines while printing black text. Tested all cleaning cycles multiple times - initially this helped. Thereafter removed head and cleaned. I tried several different cartridges, but to no difference. Not a cartridge problem. Printed well for a short period, and but lines returned soon after.

 

[websnail]

Canon MX850 Originally started showing lines while printing black text. Tested all cleaning cycles multiple times - initially this helped. Thereafter removed head and cleaned. I tried several different cartridges, but to no difference. Not a cartridge problem. Printed well for a short period, and but lines returned soon after.

Sounds more like an ink problem... That and you probably haven't quite shifted all of the clog so some of it is re-establishing itself in different nozzles.

Having a good ink to start with is definitely a help though..

 

[skorpian]

It seems the link to the manual that I posted some time ago is no longer valid - so here it is in a new location..

FREE DOWNLOAD for Canon mx850 Service repair manual and parts catalog manual link

https://anonfiles.com/file/cc8e0f5a9e7b37fa14e5451d82f6f10f

 

[LectroMan]

I have a Canon Pixma MX850. My printer prints color fine. It stopped printing black, suddenly.
I cleaned the print head, which did not help. After reading this article, I was examining the pads to the right of the print head. While poking around, I noticed a plunger switch on the far right side of the printer about 4 to 5 inches from the front. I pushed it and then released it after about 1 second. The print head started some sort of operation that I have not seen before. This op. took about 20 seconds. I tried another black platen copy and it worked, but was a little faded. I repeated this operation again and the black was darker, as it should be. What I think is that when the cover is closed the function for this switch is different than when the cover is open. I may be blowing smoke here, but this has fixed my printer, so I'm happy. I hope this helps someone else. Please post here to let others (and me) know if this works for you.
Thanks, LectroMan