I have a Bizhub C759 when feeding from trays 3 & 4 it only feeds up to the rollers in the tray and no further then will through an error 17-30, 17-40. I found a piece of paper jammed in the side door but that did not correct the issue. I have cleaned all the sensors in the paper path and was able to get 6 pages to print then it started to jam again. All the other paper tray work properly including the manual paper feed on the side with no jamming. We don't normally work on these machines so any in site would be greatly appreciated.