Toshiba E 25 Build up of toner on heater rollers

[AISI]

Working on a Toshiba E Studio 25 that's gets a build up of toner,(about 4 inch's wide) down the center of the upper roller.This has happened to me on a few of these models and i have replaced the fuser rollers,using OEM toner and developer and initially the problem goes away ,but after the customer runs some copy's for a while the problem comes back again.Has anyone else had a similar problem?Would appreciate any help? Thanks.

[ToshibaTech]

I have not seen this problem but it sounds like the cause is in the process unit. We would probably just replace the whole unit here, but it might be doctor blade or recovery blade. Also, you said you replaced the fuser rollers... did you also replace the metal cleaning roller? I assume the customer is getting this stripe on their paper before and after you changed the fuser rollers? Or did the stripe go away from their page and then come back (this could kinda rule out the process unit)?