Well, I had the impression, at the beginning, that not a single drop was going through my 4900's wate tubing. I can't tell you what it is. For me, the "magic ingredient" was, perhaps, the many removal and reinstalling of the head? Perhaps, if you remove the head once more, make sure you can inject piezo flush through each channel inport, and that you get a nice ribbon flowing on the other side. Then, I'll know you are at the same stage I was with my 4900 when none of my nozzles were showing on the test pattern. Look again closely at the tubing to see that they're actually full. Then, try an Ink Eject followed by an Ink charge. You're likely to get some errors in the process but it ought to get ink moving through the lines, if "all" is well. You can follow it up with a powerful clean. If the pump is "temporarily" out to lunch, none of this will make a difference on the nozzle check. But it will force some agitation through. My theory. Then, let the printer sit idle for a day or two. That other ingredient in the "secret of my sucess" was time, let whatever "gravity" and "physics" play its role. I wish you could simply swipe in a new pump to see whether you get any ink going through the waste line? Remember, I wasn't able to establish this, with my printer.
