u/Diabeteslen

I have a Designjet Z5400 that has been having issues. I replaced the format board, PCA Engine board and the interconnect cable. Now I keep getting the error code 86:01 saying there's a paper jam. There is no paper I. The machine, I have cleaned the encoder strip, and have lubricated the rails. When it runs its diagnostic cycle to pin point what's wrong it says nothing is wrong. Does anyone have any suggestions? Would love to have this thing up and running again.