We have a few 575 Studio Spot and Colors that are having some type of sensor issues. Syptom; fixtures power on and home but do not strike. Display reads a 'COOL' message, however, the fixtures are not hot because they were never on. What parts do I need, what do the sensors look like, where are they located with in the fixtures? ..Thanks Much!.. and sorry, Im new to this as you can probably tell, its just kind of up to me right now to deal with.