Another GS6000 black in dropout issue

[IvanDD]

Hello! So over the course of 4-5 years I've had the black ink drop out on one side of the head then the other head to follow. At one point this was happening every six months. Had decision one out several times, replaced head and damper, and everything was fine for six months. Last time they came out they replaced the head, cap top assembly and ink filter on the black line, and we've been good for almost two years. The other day it happened again, first on A channel, now on both, only black.

I can pull ink just fine through the filter, through the valve, and through the subtank just fine. I can pull through the captop. Ink seems to be flowing, but i can't get the dropout to go away.

Im sure replacing the head will fix the issue again, but why does this keep happening? I want to fix this, not just replace the head and cross my fingers it wont fail six months later.

Any help would be appreciated.

 

[IvanDD]

Someone suggested moving to STS inks for at least black and yellow, has anyone done that and has this black ink issue happened when using STS inks?

 

[Pitzu]

As I've said in another discussion, I had a similar issue with cyan channel on a Mutoh ValueJet 1614 (almost the same printer as Epson GS6000).
It was...the ink?(probably a bad lot). I had to choose between the printhead or ink replacement. I've flushed the old ink with solvent and changed it with another ink.
If it was the flushing that helped..or the ink change..not sure...but worked great afterwards. We have 9 months without any incidents.