Head of philips norelco speed xl fell apart.

Same thing happened to my father's shaver. After working on it for about 30 mins, this is how I fixed it. You need to start with the top silver piece/cover. Turn it over so you see inside of it. Drop the 3 screens into the holes upside down (so they face out). You need to rotate the screens until they sit as low as possible. Now drop in the 3 blades, again sharp side down. There should be a triangular piece with 3 circles attached to it. One side is gray, and the other side has a black triangular piece. If you look closely each leg of the black piece has a tiny picture of a lock and an arrow. Rotate the black piece in the opposite direction of the arrow. Place the gray side down lining it up with the three blades. Now rotate the black piece, it will lock into position, and hold the blades in place! Finally, the silver head has a little hinge on one side. This hinge is flexiable. Bend it to a 90 degree angle, and slip it into the notch on the top part of the main body of the shaver. Close the head part, in my father's shaver I had to press a lever in the front to snap it into place.

Hope this helps!