EK43 malfunction

Hey all,

Our shop has an EK43 grinder that hit a snag. We replaced the burrs about days ago until just before close yesterday the EK wouldn’t turn on and engage the motor at all. The ON switch remains in place if it’s connected to power and reverts back to neutral if unplugged. I’ve tried the release button above the ON/OFF switch but no luck. Left it unplugged and resting overnight incase it was a thermal overload but still nothing the morning. Any ideas?

Circuit breaker seems a cheap enough part but no point replacing it there’s something else tripping it?

Any and all help welcome!