IX6850 clogged pigment black

The purge system uses a pump to create suction in the tubing that sucks waste ink from the print head (and cartridge) to the diapers in the bottom of the printer which absorb and retain this waste ink. An airtight junction between cartridge and the parked print head would facilitate this process.

floK said:

I couldn't have any proof that I fixed it.

Click to expand...

Flooding the purge pads with solution is the test. Anecdotal evidence suggests that whether the print head or cartridge is clogged has little or no bearing on whether the flooded purge pads are drained. It also seems that little or no ink is drained from the print head in this simple procedure since the purge pads will begin to whiten, suggesting only the flooded solution passes through the purge pads. Of course this may only applies if you merely close the lid, let the printer noise finish, and then reopen the lid, ie NO cleaning cycles or printing done, but you can try whatever you'd like to compare results. AFAIK, no one has witnessed and reported the exact moment the flooded solution disappears from the purge pad of a properly functioning printer.

Has a blot test been performed on the printhead?

Remove the carts and printhead, a carefully press it only a tissue to see if there is pigment ink at the nozzles...

turbguy said:

Has a blot test been performed on the printhead?

Remove the carts and printhead, a carefully press it only a tissue to see if there is pigment ink at the nozzles...

Click to expand...

Unfortunately, no trace of black pigment, neither after the print head has just been removed from the printer, nor after 30 hours of soaking in cleaning solution.

In fact - as I more thoroughly described in post #13 and in the beginning of post #18 - the pigment ink even doesn't penetrate from the cartridge into the print head, due to the obstruction (clog) in the inlet filter.

All my attempts to dissolve/remove this clog remained unsuccessful...

I once had a complete clog of the BK (in my MG8250) - strange enough after rinsing under the tap for a clog in other colours, I never do this again only demineralised water since - which I could not clear with a week soaking.
I decided to dedicate the printer for scanning (it has a CCD scanner) and photo printing, reinserted all the (full) cartridges and forgot it.
After a few weeks I saw some life in the BK nozzle grid, and after a some cleaning instructions everything was back.
Probably ink (and patience) can solve obstructions in the printhead.

As stated in other posts, I had a solid clog in the pigment side of a Canon purge unit. It required disassembly to access the purge pump. This is a peristaltic pump, which can't pull much of a vacuum, as it relies on the "rebound" properties of the tubing within the pump chamber to do so.

The solid clog was found to be in a 90 degree bend of the plastic manifold that connects the purge pad tube to the peristaltic tubing within the pump. No amount of "soaking" with popular solvents had any impact. This clog had to be cleared with a very fine wire, pushed into the manifold to force out the solid. Once that path was clear and the printer was re-assembled, everything worked again.

A probable cause of the clog was using a older formulation of HobbiColors pigment refill ink that had a tendency to solidify in small passageways.

I mention this "experience", as the print head itself has very narrow passageways. If you have a sold pigment clog in the print head, it may have to be removed mechanically. That can be fatal to the print head.

floK said:

30 hours of soaking in cleaning solution

Click to expand...

What are the components of your solution?

@ stratman: 80 ml of distilled water, 20 ml of isopropanol and 5 ml of ammonia-based glass cleaner. Maintained at a temperature of 50 -55 C, on a radiator.

@turbguy:
Thanks for the description, maybe once I'll have the time and courage to disassemble the printer and to fix the purge system, so your information could be precious.
However, I hope to find, before, the service manual for my model, I would be much more confident.
And maybe, with some chance, a method to enter the service mode will become available...

@palombian:

You were very lucky, I kinda lost my hopes to have this chance... but who knows?
However, if you say you used the printer only as a scanner and for photo printing (which, as I know, means using only dye inks), how was possible for the pigment ink to circulate through the print head and unclog its correspondent nozzle?
That's a mystery for me, as I would expect things to happen exactly the opposite, respectively clogging to worsen and become permanent...

floK said:

80 ml of distilled water, 20 ml of isopropanol and 5 ml of ammonia-based glass cleaner. Maintained at a temperature of 50 -55 C, on a radiator.

Click to expand...

I recommend liquid dish washing soap such as Dawn or Fairy and water. That's it. Use a non-metalic, non-reactive bowl and fill to above the ink inlets of the print head. I also wad up a paper towel and place in bottom of bowl and rest the nozzle end of the print head on it. Every now and then I will pump the print head up and down on the paper towels to drive solution through the nozzles in the print head which simultaneously helps move solution through the ink inlets.

Not sure I would keep it on a radiator as this might cook the pigment and help to keep it solid. I will occasionally heat the solution to Lukewarm in microwave without the print head. Change the solution at 12 hours or sooner if dirty.

Let soak for at least 12 hours, if not 24 hours, the first time. Flush with water and let dry so electronic contacts are not wet at all. Patience is key!

It might be you have cooked the pigment ink to an undissolvable mess and your last hope is disassembly of the print head. Expect failure but hope for success.

Then there is still the issue of your pigment ink purge malfunction to deal with. If you do not resolve that then there is no sense in fussing around with the print head.

The options for you have been presented. All you need to do is choose your path.

floK said:

...

@palombian:

You were very lucky, I kinda lost my hopes to have this chance... but who knows?
However, if you say you used the printer only as a scanner and for photo printing (which, as I know, means using only dye inks), how was possible for the pigment ink to circulate through the print head and unclog its correspondent nozzle?
That's a mystery for me, as I would expect things to happen exactly the opposite, respectively clogging to worsen and become permanent...

Click to expand...

Inkjet printers purge all colours wether they are used or not, so you need to provide a filled cartridge even for the ones you do not (plan to) use.
You have no absolute control over this use either.
The only way to prevent burning of those unused nozzle rows (and the end of your printhead) is to mask the corresponding electrical contacts.

It is perfectly possible to use a printer in "limited mode", although it depends from what colours are left.
My son runs a MG5250 intensivily with photo black switched off since 2 years (for office B/W and colour single side).

Interesting, thanks!