Started working on a machine that will print from 1 to 10 pages then stop. Always stops just into registration or up to the top of page sensor. Have already tried new rollers,paper drive assy., tray 2 solenoid,paper feed assy.(behind the manual tray), and registration assy. I updated the firmware. I took it apart to clean the top of page sensor, although it works in the sensor test. I don't see a replacement part listed. These were either new parts or from a known working p4015.<br>This is connected to an optional third tray which works flawlessly. Manual tray works as well. When I started working on it, a lot of pages had to go through before it stopped. Now only a few at a time will run. Has anyone run across such an odd problem?