Don't know,but I have a P 618 and have had similar problems,open the lid,in front of the right hand lower hindge you may see a tiny black microswitch button sticking up(the size of a pin)run the machine and press the button down and release,wait until it responds,if no response try again,opening the lid activates the machine and the little button does that job.Try it you have nothing to loose,relist your prob if you have no joy.
Rich, March 2008