Try to find another 4250 and use it as a model to connect the wiring. Its far easier and faster than using a schematic...
I fix all brands of roll laminators for a living around pittsburgh and have seen customers dewire things:(
Using another identical model machne reduces the risks of mistakes which can blow the main board a 600 dollar mistake that junks the machine
bob haller service and sales pittsburgh pa 412 366 4906, February 2013