I just installed the Gloss optimizer cartridge in my SC P400. I’m getting a failed nozzle check for that position. When I first primed the cartridge I got a small stream of bubbles introduced into the cartridge while I withdrew ink from the exit port. This produced a foam like layer of bubbles at the top of the cartridge. It seems that the air was coming in from about halfway up the cartridge below the vent hole. The other cartridges “primed” as would be expected and are working normally. The nozzle check for GO is not producing the “checkerboard” pattern, and when I print on glossy paper with gloss optimizer turned on I can feel that no GO has been put on the paper.
We’ll get you out another P400 GO cart pronto.
I’ll be in touch Monday to get that GO cart back so I can dissect it too.
In the inter-im, if you still have your Epson OEM GO cart, it will work as a short-term replacement.