Hi all hope someone has seen this very weird issue before as I am baffled.

I arrive at the machine and it shows jam in tray 1(Manual feed tray).
The jam is cleared by dropping down the green duplex assembly after removing the paper tray (Tray 2) and then pressing O.K
The machine then cycles comes to ready and goes into jam again even with the manual feed tray closed up and obviously no paper present.
If you clear that job out of memory it comes to ready but says add paper, I then put paper onto tray 1 and the machine says insert tray 2 which is already there, so it obviously cannot see this.
However if I now remove the paper I have placed on the manual feed the motor runs but the feed roller does not turn or paper lift and it goes straight back into Jam tray 1

I am very confused.

Cannot see a switch unseated, have checked the spring on the manual feed paper present switch and reseated it so I know it is in the right place.
Have removed and checked all round and underneath the transfer belt. The flag on the cassette that makes the rear sensor is in place and I also tried fooling that sensor all to no avail.

Any clues would be most appreciated.

I am thinking it may be board related as it appears that the switches are working with reverse logic