Recently my MBK head was giving trouble ( diag. patch looked grainy and soft on the edge) After a chat with HP the replaces the service station (under warranty) and the left spittoon. I didn't think it was the issue but I let them do it. Things looked a bit better but not great and wasn't happy so we replaced the head (Under warranty) aging this seamed to make a smaller difference so i think but cant really tell, but still not happy with the patch but prints come out alright. After a day the low yellow needed to be replaced. Things were fine until last week when a job just suddenly had no yellow at all about halfway through the print. I diagnostics test showed almost no yellow at all. I could not believe it, of some googling i figured i should just print another diagnostics and bobs your uncle 100% perfect like new. Back to printing, on my first 2 copies 100% , 3rd copy of same image the yellow bombed out 2/3rds of the print and into the next copy (nested). Then a head clean and cleaning the contact points and try again, still same issue!
My experience says:
it's not a clogged head its electronic. (easy) as it intermittent. waiting for new yellow head to arrive regardless.
could be a faulty carriage PCB (voltage issue) ?
faulty wire connection from the new service station?
carriage ribbon cable issue?
contaminated yellow ink as was recently installed(expiry 2019 though)?
is it the heads own electronics? can they act up like this.
What do you think!?
Hp wants me to replace half my heads (recently expired) before coming out.
