MG6250 - Magenta disappeared

[MP640]

I ran into the following situation.

After printing a 4" x 6" photo, I noticed some stripes. I did a nozzle check and found some missing lines in magenta. After a cleaning cycle and another nozzle check everything looked ok again.

The next photo had very weird colors. I did another nozzle check and magenta was completely gone (3 magenta bars were missing in the nozzle check print). Suspecting an ink flow problem I took out the magenta cart and blew in the air vent which caused ink to drip out of the outlet hole. After a cleaning cycle, the nozzle check still didn't show magenta bars.
I took out the printhead, put a tube on the magenta port and forced water through it until I saw it coming out of the head. Dried the printhead, reassambled everything and after a cleaning cycle the nozzle check was perfect again.

I didn't print any other photos yet. Did print some A4 and it still looks ok. But then, photo printing requires much more ink than text.

I would like your thoughts on what happened here. How can I loose one color all at once? I'm still thinking of a cartridge inkflow problem, maybe if I didn't flush the printhead but waited the problem would have solved itself when the cartridge stabilized?
Is there a way to test a cartridge for inkflow problems? This one was on its first refill after a purge.

Thank you!

 

[Grandad35]

Is there a way to test a cartridge for inkflow problems?

With the cart removed from the printer, wipe the area around the vent (so that you don't get ink on your lips), hold the cart over a drip pan, then blow into the vent until ink drips from the exit. Was the ink foamed? Remember how much pressure that it took to get the ink to drip. Repeat with a known good cart. Did your magenta cart require more pressure than the good cart to get it to drip? Can you take a photo of the side of the cart showing how empty/full the sponges and ink tank are, then post it on the forum? Did you run this cart to "empty" before the 1st refill, or did you refill before the ink tank emptied? This sounds like an ink delivery problem in the cart.

You may want to read this thread.

 

[The Hat]

It’s not uncommon to have an ink flow problem with a cartridge especially after it has been purged for any number of reasons !

In your case you shouldn’t have removed you print head at all because your diagnosis of your problem was correct in the first place (Cartridge trouble) so you should have concentrated on that to start with.

When you have poor ink output you should always suspect the cartridge (99%) of the time first and only the print head 1%, you can only get a clogged print head from lack of use or very poor quality inks, but a cartridge problem is usually down to how it was incorrectly filled and maintained (Unknowingly of course), I’ve been guilty of that crime on occasion myself.

A nozzle check uses so little ink that it’s useless at detecting poor ink flow and it can only tell you if you have a clog in one or more of your nozzles, the best method to use for checking out a cartridge ink flow problem is to print a 2.5 cm x 20 cm strip of that colour on plain paper and if it fails that test stop the printing immediately by pressing the resume button, don’t wait for it to finish.

@Grandad35 has given you a great tread to read on the filling and checking and maintenance of your cartridges here. this thread.

 

[MP640]

I read Grandad35's thread and can confirm that I also conduct the two tests that are mentioned:

1. cover the top fill hole with your finger and release above a sink to check the dripping frequency;
2. blow in the vent holes.

The magenta cart passed both tests after the refill. Dripping about one drip per second and blowing in the air vent didn't require much pressure.

I always swap all cartridges as soon as one of them gets the "!" in the ink monitor. So maybe I should no longer purge the cartridges?

 

[The Hat]

If an ink flow problem exists then the only way to solve it is to reappraise your whole purging and refilling procedure and see if you can figure it and correct the problem, I had to purge three time to get a satisfaction result !

 

[MP640]

ok. I just purged a set of cartridges yesterday. They are drying right now with the paper towel method. I wil lmonitor the first refill closely to detect any anomalies.