Those have already been replaced, several times with no effect.
Three new fusers and drums have been installed, along with the transfer roller and ALL of the circuit boards have been replaced. We have attempted all of the avaliable drivers on the Xerox website. Every internal page that comes from the printer is fine. However, printing over the network or USB connection comes out with the ghosting issue. Even the Xerox partner service vendor we are working with has gotten the ghosting prints when they connect their service laptops up to the printer to print their own test pages. I'm seeing this ghosting issue on nearly 90% of our printers and even our other remote offices, after talking to them, have said that their same Xerox 4600's are ghosting.
The final thing that Xerox is suggesting to our service company that they are sending out a differnt type of toner and a new drum. If that still does not fix the issue we are then going to request a tech from Xerox examine this issue on site. This is something that is appearing to be impacting a large percentage of our printer fleet at all of our office locations, which is pushing some 50+ printers.