Another thing you have to check is the linear resistor - ie the sensor that detects the focal length. If the ribbon is loose from its connector, it may not giving this information. So it is stuck at a specific focal length. You can check if this is it, if the you can see picture on the LCD before you rotate the lens to the normal shooting position. I mean, when the lens is in its OFF position. In order to access the aformentioned connector you need to: 1) Remove the back cover 2) carefully remove the ribbon that is attached to the outer contacts by lifting up the lock mechanism on the back side of the connector (the opposite side of where the ribbon is inserted). 3) There are 2 connectors remaining, the smaller one is the one to check.