Do I have to conduct EFA with already established scales?

#1
I am doing a study involving a predictor including three already-established scales for that predictor, and I am going to perform multiple linear regression after that. I am wondering if I have to conduct (Exploratory Factor Analysis)EFA with already established scales before I add the items together in all three scales ? If so, do I have to do only ONE Factor Analysis for all scales including all of scales' all ITEMS? and any way that can help me achieve the validity for one factor solution approach?