Just a shot in the dark. Unless the motor literally burned out, if you haven't checked these two thngs, don't throw it out yet. Your motor may have a thermal override switch (a little red button on my motor which is a 15 year old Craftsman radial) which will kick out if the motor is working too hard, and, 2. dust in the motor contacts. On my machine the button doesn't pop out enough to visually tell whether it has popped. It won't reset until the motor cools enough and it takes a lot of pressure to reset it when it does (it will click.

A little dust in the contacts will bring things to a halt quickly. The solution is usually just a blast of compressed air into the end of the housing where the contacts are.

Cheers.