1] After frequent stop/starts motor 'reved' and could only be stopped by pulling wall plug.
2] Have checked supply to brushes seems ok.
3] Relay switch has power at terminals 2,3 & 4 but not 1 in either switch state.
4] Fine windings look a little dark compared with main windings.
5] Can it be fixed or can U buy replacement switch motor parts?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix circular saws.