A friend of mine asked whether I would repair their camera. After dropping the camera, the zoom did block operation. After switching on the camera, the zoom tried to extend. Though as the soom got stuck somewhere in between, the camera retracted the lens and switched to error mode.
I agreed to do my best to restore operation. Unfortunately this task got more challenging as I expected:
I had to fully disassemble the camera, to reach the zoom barrels. The zoom barrels (made of plastic) have a sophisticated set of guides to operate the lens. That said, the pattern set up defines the movement of the front and center lens assembly, to focus and / or zoom. By dropping the camera, one of the tiny guide pins got pushed to the wrong aisle. So the camera could not move the lenses and barrels freely. As most of these cameras detect an overload, and the Lumix DMC-TZ20 does this as well, the camera retracts the lens for protection and sets error mode.
By repositioning the barrels and lense assembly (which was not at all an easy task), the camera could return to normal operation!