HP yellow inks SEEM to be excessively corrosive.
I have had a DesignJet 450C for quite a few years now, and
the yellow carts have alwys been the most problematic.
I posted a question to the printer guru at fixyourownprinter.com
and he and a couple others confirmed the problems with yellow
ink...here, it manifests itself most commonly as a cart that refused
to print AT ALL. Carts usually plug up some, causing streaking,
but these were completely dead.
Checking the carts via the PC pads that make contact with it
showed that somewhere the copper traces had opened up, likely
due to the yellow ink.
So, I've just learned to live with it.
As far as maunal cleaning goes, if the damn thing's not working,
I figger you've got nothing to lose.
I can USUALLY revive a dead cart (unless it's an electrical problem
as above) by wiping the printhead FIRMLY several times with a piece
of toilet paper (yeah, I know, that's supposed to be a BAD THING, but
it works).
If that doesn't work, take the cart OUTSIDE, somewhere that flying ink
will not get on anything critical, and pretend to "throw" it with the
printhead
facing away from you several times while NOT actually letting go. The G
forces will often get things flowing again. A large arc with the bottom
of
the arc
toward the ground works well, and the ink doesn't get on anything vaulable
this way.
Then follow up with the TP as above.
I've revived MANY $35 HP 5164X carts this way.