The motor on my Grizzly 1276 sander (1725 RPM) shuts off just about the time it gets up to speed, about half a second after I turn it on. If I turn it off and back on quickly, while it's still spinning, it runs normally. Grizzly says it's a damaged on/off switch; I'm skeptical of this because it happens every time, not intermittently, and it started happening suddenly, every time, plus (primarily) the fact that it runs normally if I turn it off/on. Anyone know what could cause this? I don't understand electric motors, except that some of them have both start and run circuits/windings. Could it be these?