DWS782 DeWalt Miter Saw - How and When to Replace Brushes (Part # 614367-00)

http://mmtoolparts.com explains what brushes do, how to know when to replace brushes and how to do it yourself. Anyone can do this at home. If your tool is experiencing intermittent power (sometimes it works, sometimes it doesn't) or decreased power, it's a good idea to start by inspecting your brushes. 

*Parts will vary depending on your model/type #:

DWS782 type 20 - Brush Part #614367-00

https://www.mmtoolparts.com/store/dewalt-brush-lead-614367-00