Probably the easiest diagnosis and fix ever - when I removed the bottom panels half of the old arm was lying on the floor. Then it was simply a matter of finding and ordering the part. When the part arrived I removed the retaining clip with a small screwdriver, slid off the remainder of the old arm, slid on the new arm with the solenoid plunger in place, slid in the retaining clip with needle nosed pliers and closed up the machine.