Yet another issue with my Pro 10 paper weight. Been idle since last July; and unplugged since Xmas; so I knew it was going to have problems with clogs. My last good prints was 10 months back before going on an extended roadtrip (hence the idle time). After going thru much (OEM) ink and replacing half the ink tanks running dry; PBK does not print at all on test (just the side bar). PBK was not empty; but I replaced it with a new OEM tank after having no initial luck on a print pattern (after all the others now worked). All other colors are now printing fine. To arrive where I'm currently at, I've performed several cleans and several deep cleans (several, meaing about 8-10 each). I also removed the printhead and passively cleaned the bottom exit points, and the top inlet (from the tanks) with windex, isopropyl and distilled water. That actually got everything (but PBK) working as it should. I also allowed the underside of the head to soak in isopropyl for an hour (and kept the top side inlets moist). Before reinstalling, I sat the printhead outside in the dry Arizona 100 degree heat (not in direct sunlight; and no dust) for a 30 min dry. Before someone wonders if I damaged the printhead thru carelessness; scrub that thought, I worked +20 years on avionics, and another 18 years on Nikon Lithography toolsets for Intel Corp; I'm competent. I currently have the printhead back out, and letting soak in isopropyl for 4 hours, and will then soak it in Windex overnight; and will do a final rinse with isopropyl and then dry before trying again. Does anyone know of a signal problem feeding to the printhead affecting just one color? And if so, does anyone have any idea which contact is feeding PBK on the circuit side of the head...and the origination point? I've ran thru at least $800 in ink, all for about 70 prints over the past 6 years. If not; then I guess my last attempt (unless the overnight soak works) will be to take a chance of damaging the printhead by using a soft bristle brush on the PBK outlet port. But; I really don't think there is a clog; I'm able to direct compressed air thru the bottom and see ink pool at the top sponge/inlet. Thoughts? Hopefully I can get it up and running again; produces nice prints; but I honestly wasted my money.