I have the WC7545 machine.
Since a few weeks, I've noticed some black marks that are left on printed pages. It does'nt matter which tray the paper comes from, the marks may appear. It is not systematic on all printed pages, but still a concern. Also, the "intensity" of the marks is variable. The marks may appear when printing one side only or when printing on both sides.
I tried to print the problem pages, but didn't quite figured out what was the issue. It lloks like something is dirty and leaving marks on the paper when the sheet passes through the faulty/dirty component...
Thanks in advance!