i have a dm150 rowenta accupress iron?

I took it apart and a small spring with round metal head fell out and I don't know where it came from.the spring is probably 1/8" long.it looks like some type of spring for a button making contact with electricity but I don't see any place for it and can't find pictorial diagram because it's 10 or 12 years old but wasn't used much.thanks,Bob w.