Canon Pro-100 Nozzle Check stutter pattern

[SV_Trinity]

I'm hoping the experts here can help me figure out the stuttered pattern on the CYAN channel.
What might be the cause ? What are my next diagnostic steps ?
Thanks to those whose posts I've read thus far ...

HISTORY:
Precision Colors in OEM Canon modified cartridges.
Have tried cleaning printhead (windex, distillled water) with resultant perfect Nozzle Check, but shortly afterwards, this CYAN pattern returns.
Have tried two sets of OEM modified cartridges.
Have dripped windex to Waste pad and confirmed ink is pumped away.
Have confirmed CYAN ink is flowing (drip drip drip) when silicone plug removed from drilled hole of modified cartridge.

NEXT:
Have ordered an new Canon OEM CYAN cartridge to rule out bad sponge in modified cartridge(s).

 

[The Hat]

Have ordered an new Canon OEM CYAN cartridge to rule out bad sponge in modified cartridge(s).

The new OEM cyan cart will be your last resort, if you run 5 or 6 test prints and the nozzle check doesn’t improve then only a new print head will solve your problem..

The print heads in these printers are not designed to last for ever…

 

[SV_Trinity]

The print heads in these printers are not designed to last for ever…

Thank you for replying .... YOU were one of the experts I was hoping to hear from ... HAHA.

The printhead isn't actually that old ... less than 1900 prints. What I couldn't figure out was why the NozzleCheck after printhead (windex) cleaning was "perfect". But after a couple of weeks of intermittent (infrequent) printing, the "stutter pattern" returned.

I was encouraged during the printhead cleaning because I noticed this ... I soak a thick folded paper towel with windex .... then place it in a tray. (Windex only in the paper towel). I sit the printhead on top, and let the windex fumes soak into the printhead ... I see the paper towel soak up the ink from the printhead. What I found promising was when I pushed down on the printhead ... I could see the windex coming up each color channel. This makes me think the printhead is not clogged. Does this make sense ?

 

[The Hat]

NozzleCheck after printhead (windex) cleaning was "perfect". But after a couple of weeks of intermittent (infrequent) printing, the "stutter pattern" returned.

I reckon your ink may have something to do with the problem, try purging the cyan cart and see if that makes any difference..
It’s quite possible some of the old ink has dried hard on the nozzles and why I suggested the OEM ink which might clean and free it up, plus depending on how your store your refill ink and age, it might have gotten a build-up of crud (Algae) over time..

 

[SV_Trinity]

I reckon your ink may have something to do with the problem, try purging the cyan cart and see if that makes any difference..
It’s quite possible some of the old ink has dried hard on the nozzles and why I suggested the OEM ink which might clean and free it up, plus depending on how your store your refill ink and age, it might have gotten a build-up of crud (Algae) over time..

YES .... I think your are on point ... I was wondering about this, but wanted expert reinforcement. I'm going to windex /clean the printhead and then run OEM ink to test.