"The Yellow" strikes again

[floK]

Hello everyone!
I have already told here about the yellow ink missing problem that led me to throw my previous Pixma IX6850 and buy a new IP7250.
Well, my new IP7250 worked impeccably for months, until... I had to go on vacation and leave it unused for 3 weeks. On my return, I found that the yellow is missing again and, with all my efforts, I'm unable to fix the problem.
Here's what I've tried so far:
1. I blew easily into the cartridge (through the vent hole) to test if it is a drying issue. It wasn't - a drop of ink fell immediately on the paper underneath. And the cartridge is half full.
2. I removed the print head and soaked it for 4 hours in a 50% solution of isopropyl alcohol and 50% demineralized water. Result: I managed to get yellow in the nozzle check print, but with a large white stripe almost in the middle. Worse, this time appeared problems (missing lines) also in the black pigment pattern...
3. I removed again the print head and, this time, I soaked it in a solution of 50% of glass detergent with ammonia (similar to Windex) and 50% demineralized water. Result: now the black pigment is ok, but the yellow has completely disappeared, without any trace.

Thus, I suspect could remain only two causes:
1. The clogging occurred somewhere in the inlet port of the printhead, where it can't be removed by the usual soaking;
2. The "yellow jello"...
(As for the second possibility, I have to specify that I use the ink from OctoInk (probably Prodinks) and that it is the first refill of the original cartridge, which I made when about 25% of the original ink was still inside.)

So, my idea to solve both these problems in only one attempt is to remove the ink from the cartridge and to fill it with Windex 50%/dem. water 50%, then to put it back in the printer and, after several hours - in which, hopefully, the solution will start to penetrate the inlet port - to try one or two cleaning cycles.

Do you think it's a good idea, or is there a risk of ruining the print head?

 

[The Hat]

Do you think it's a good idea,

Try soaking your print head in a plastic dish filled with warm water and a squirt of fairy liquid and cover the ink inlets also, and then leave it to soak overnight.

Before re-installing the print head, shake off the excess liquid and dry it thoroughly with a little heat, and only when you’re sure the head is dry then install it in the printer.

While your soaking the print head cap all your cartridges to stop them drying out, and I would use another yellow cartridge till your sure that’s not the problem and put a couple of drops of soapy water on the ink inlets before inserting the cartridges again.

After the printer has settle down run a nozzle print, and check it against the previous one, at this point it should be greatly improved, if not let the printer stand for an hour or two before printing another nozzle check...

 

[stratman]

Always post a cropped scan of your nozzle checks.

This sounds like a cartridge-based issue with ink starvation. Try a new Yellow cartridge first before soaking. Flushing and refilling the old cartridge is another solution.

If the new cartridge does not resolve the Yellow issue then use water and liquid dish washing liquid for soaking the print head as The Hat said. Let it soak for 24 hours AT LEAST. Forget the high concentration alcohol or ammonia soaks.

Forget the extra "heat" to the print head as The Hat suggested. You might damage the print head. Have patience.

put a couple of drops of soapy water on the ink inlets before inserting the cartridges again.

That's a new one to me. Why?


Edit:

 

[kdsdata]

Apologies for off topic, but @stratman I just love your avatar. I have a pair of scissors from my youth, from an incident with a cord. Thanks for the chuckle.

 

[floK]

Ok, thanks @The Hat and @stratman, I will follow your suggestions one after the other, starting with the cartridge flush.

But, to my knowledge, could you explain why you don't agree with the method to test and solve both possibilities in one step, as I proposed at the end of my post? Do you consider it dangerous, or just ineffective?

 

[kdsdata]

Rule #1 of Troubleshooting: Do "one" thing at a time, so know what works. Otherwise you might get a fix, but you won't know which step did the trick, and you will find yourself doing the individual steps somewhere in the future anyway. So spend the time the first time. Good luck.

 

[stratman]

Thanks for the chuckle.

It makes me laugh as well. Thank you!

 

[stratman]

explain why you don't agree with the method to test and solve both possibilities in one step, as I proposed

First, the forum consensus, which is probably from a couple of specific members, is that cartridges filled with a cleaning solution may cause less good than soaking the print head itself and may actually harm by increasing the risk of nozzle burnout as the cleaning solution may not have the same cooling properties of ink.

Second, I think your issue is more likely at this time, based on the limited info you have provided, to be related to a poorly functioning cartridge.

Third, you enjoy trying things with your print head, some of which are not advisable based on forum advice. We've been down these roads before. This is not to say that these things are absolutely contraindicated. However, there is anecdotal evidence of other gentler and effective means for you to utilize that have relatively predictable results for us to help gauge what is happening and what to do next.

Still, refilling retains an individuality which embraces the adage "YMMV".

 

[floK]

Well, I really don't enjoy to "try things" with my printhead, please believe me
The only problem is that, in the past, some of the agreed methods on this forum didn't work as expected, for me (or didn't work at all).
So I just try to understand the principles and the safety limits within I could experiment with other solutions, maybe more suitable for some particular problems...

 

[palombian]

I only can say that I also had issues who could not be explained or solved by the forum consensus.
Maybe there are things we don´t know yet.

I had issues as @floK described with yellow also, but thought to have solved them by changing from Prodinks to OCP, but it reappeared with cyan and magenta and became worse by switching to OCP ink.
Not with PBK, where I did not change inks.

The symptoms indicate ink starvation, but probably in the printhead and not in the cartridge.
Interaction between different inks, cleaning products, water, are possible causes.

Did the composition of the inks change (they had a stronger smell than before) ?