We are going to replace the maintenance kit and then run the clean cycle three times. If that doesn't do it, I will start taking it apart and cleaning it manually.
I looked up this problem in the service manual and I'm getting very different advice. The very first thing your link suggests is actually the very last thing to check. What I should be checking are the exit rollers, the lower duplex guide and stripper blade. I'm currently going through the manual to understand how to do these things.
Thank you for using the Support Forum. Please take a look at the solutions for smears and make sure you have tried all of them. If the do not help then please consider contacting your support centre for further assistance.
Our ColorQube 8570 is printing sheets with black ink smudging the page. The pattern seems to suggest a dirty roller, but I'm not sure which rollers. I tried the automated cleaning procedure for smears three times and it still is printing these sheets: