Could be a number of possibilities from the power cord, the switch, any possible safety devices, radio suppressor, any electronics through to the motor brushes.
A 4 inch grinder doesn't take long to take apart and this would probably be the best thing to do initially to ensure there are no obvious problems like worn or sticking brushes or poor electrical connections.
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Could be a number of possibilities from the power cord, the switch, any possible safety devices, radio suppressor, any electronics through to the motor brushes.
A 4 inch grinder doesn't take long to take apart and this would probably be the best thing to do initially to ensure there are no obvious problems like worn or sticking brushes or poor electrical connections.