The Tour headlight is a standard Yamaha item (e.g. SR500) that has been around for decades and is nearly indestructable. Even crashes leave it generally unscathed or at least still serviceable. Not even the glass breaks. I know; beentheredunit too often myself. So, even if it is defective, it is easy enuf to get an new one or parts or to repair it.
there are so many connectors inside, that one could easily be rattling against the casing. Apart from the two large mounting bolts, I don't remember any necessary screws inside. there might be a ground connection; I forget.
The reflector part has two screws retaining it in the front ring and the adjustment screw with its coil spring. It also has the snap spring retaining the bulb and three springs retaining the reflector itself in the adjustment ring.
The only parts that cause trouble in my experience are the two "hinge" screws holding the reflector in the adjustment ring. I replaced them with M5 bolts with selflocking nuts and
disc springs.