Hi Randy,
being a saw, i'd be suspect of the main switch.
to test, disconnect power, get an ohm meter and inspect the power cord and plug connections
take a phase to phase reading at the cord to see if there is a short
take a phase to ground reading for each phase and see if there is grounded out wiring
remove the either incoming power cord or the motor cord from the switch, so that you can test the switch.
testing the switch,
most saw switches are linear in operation. the top 2 terminals are one pole, the next 2 terminals down are pole 2, the third set of terminals are the pole 3
with the sitch on the off position test the 2 top terminal together the meter should read open, then flick the switch and retest- the meter should read low resistance
repeat for each subsequent pole, noting any variations
reinstall wiring and tighten the incoming power connections if these tests are sufficient.
a visual inspection of the motor and associated connections are important, if no obvious faults are seen you can test the 3 phase motor.
testing the motor,
test pole to pole with an ohm meter, then test the last pole to the first pole- there should be resistance measured on both poles in respect to the first.
test pole to ground of the motor frame to each pole, there should be no continuity in this check.
should there be an open in the winding of any of the 3 motor poles, the motor will need to be repaired or rewound
reconnect motor power cord to switch and tighten connections if the tests showed no faults
i wish you the very best of luck!