Grey in nozzle check where it should be cyan!

[JohnBB]

Title says it, really. Canon TS 6250 (European , if that matters.) Carts are PGI-580, CLI-581
Everyday document printing and I notice the colours are wrong, not blue enough.
First thought was the cyan cart was empty/dry/faulty, so did a nozzle check.
My prn [like many] does a grid of black with the main black [PGBK], and two shades of both cyan and magenta (deep and light) (and one of yellow and one of grey [BK]).
Now my prn is printing a deep and light grey instead of cyan. They are well printed, like the other colour bands, in fact the 'deep' grey [that should be deep cyan] is identical to the grey [BK] band.
The cyan cart definitely has cyan ink in it, and it is wet with it at the cart opening, I've checked!
Since the nozzle check is internal to the prn, it cannot be a printer driver etc fault, so can the internal processing have somehow mixed up the command to print cyan with the command to print grey?
Or what is happening? Any ideas on a cure, please? (I did search for a similar occurrence, but did not see anything here.)
Thanks,
John

 

[The Hat]

Any ideas on a cure, please?

Try posting up your last nozzle check please..

 

[Artur5]

Since the nozzle check is internal to the prn, it cannot be a printer driver etc fault, so can the internal processing have somehow mixed up the command to print cyan with the command to print grey?

No, that’s impossible. Grey has only one row of nozzles (let’s call them big nozzles). Cyan has two channels (one of big of nozzles and one of small ones). Both rows are connected to the output of the cyan cartridge. If the problem was a rare ‘bug’ in the driver or firmware and the printer used ink from the grey cart instead of the cyan, it would eject the ink from the only grey channel (big nozzles) and both bands would be of the same intensity ( deep grey). Instead, you say that the bands corresponding to the cyan ink appear in different tones of grey (deep and light), meaning that the ink is being ejected by the two rows of nozzles corresponding to the cyan cartridge.

The most logical explanation is that there’s grey ink instead of cyan in the cartridge, but you said positively that this isn’t the case.
Nevertheless, to be sure, if you have a new spare cyan cart at hand (better if OEM). replace the current cart with the new one and see what happens.

If that doesn’t fix the issue, what can be then ?. There’s a very remote chance that the internal cyan channels connecting the cart to the rows of nozzles, developed a leak, because of a faulty rubber grommet and the cyan ink mixes with cyan. That seems unlikely because, in that case, both the cyan and grey bands on the nozzle check would be similar ( greyish-cyan, so to speak).

Another possibility is cross contamination on the bottom plate of the printhead. Grey ink is overflowing and covering the cyan nozzles. It could happen if the purge pad is dirty. I’d perform a cleaning cycle and clean the purge pad, wiping it with towel paper soaked in water. ( you'll possibly need the help of a flashlight and fine tipped tweezers). Anyway, first of all, please follow @The Hat’s advice. Upload here a scan of your nozzle check.

 

[JohnBB]

Scan attached.
I took the cyan cart out and pressed the paper with the nozzle check against the wet pad, I then smeared the resulting very dark mark with a damp cotton bud.
HTH