Canon 525/526 printers repeating clogs

[stratman]

Curious indeed.

At this time I would suggest further soaking of the print head. It won't hurt.

How I soak the print head: https://www.printerknowledge.com/th...else-opinions-needed.12571/page-2#post-108623

 

[palombian]

If the carts are not to blame, then soak the head in warm water and Fairy liquid soap for a couple of days and make sure to cover the ink inlets...
While the head is soaking print ten test sheets on your IX6550, with the suspect carts installed.

@The Hat, you got it !

The cartridge tests on the IX6550 are without (or at least less visible) faults on high quality settings, but show starvation in the cyan in standard quality (see prints nr 10 and 11 below).
I did the test with 4 different freshly filled cyan carts (with new OCP ink) and all produced exactly the same image.

My OEM carts were ages old and apparently unreliable.

After replacing my own refilled cyan and magenta carts the nozzle check came back and clearly shows starvation in the cyan.

This should IMO reduce the problem to the refilled cyan carts.
I am drying another one to pinpoint this.
First of all I will let dry it longer.
Second I will try other ink.

 

[palombian]

After bathing the 2 heads for 3 days in demineralised water with dishwashing liquid, I installed them again.

The MX895 (C with Prodinks ink, others OCP) gave one good nozzle check and one good cartridge test.
In the second cartridge test the cyan already showed starvation and the next nozzle check had blank cyan.

Th IX6550 (C with OEM ink, others OCP) a first nozzle check with incomplete cyan, the second with blank cyan.
Blowing through the vent hole and a cleaning cycle did not solve the problem.

All other colors perform as normal.
Since they were refilled the same way, I doubt this is the cause.

I tried 3 different cyan inks. The only thing I can imagine is a reaction between them in the printhead that is nearly unresolvable.
Sadly enough these 2 printers were nearly new and performed well and started developping the starvation in the cyan when I loaded them with other ink (in this case OCP).
A probable cause is the reaction with remainders of the Prodinks cyan (although the heads were stocked with cartridges filled with conservation fluid), or with the water/dishwashing fluid used for rinsing.

I would try to find out where the problem is, but after a week I am afraid this is not economical.
I do not see much use for dye ink printers anymore (the ink fades after a few weeks), and my investment (in money, not in time ) was not high), so I will rinse the 2 heads again and store the printers as future archeological findings.