I have a strange problem in konica 7085, the machine suddently doesnt sense document feeder at all. checked all the boards in DF with another working machine and all boards, sensor seems working fine in the other machine. Finally when i go to soft switch 18-4 and enable it to "0" which is ADF faulty part isolation then power off & on the machine works fine. The machine works fine for couple of weeks and comes back to the same state. If any one has solved this problem, kindly help me out.