[jergofish]

Try this, switch on the pump and see if you can hear a hum or feel something with your hand on the pump. If you can "feel" the pump turn on, you're getting electricity. If you can't "feel" the power at the pump, the next step would be to get a voltmeter and actually check the connector at the pump.

If you've got power it's possible the pump may still be good but have something stuck in the impeller causing it not to pump. You'll have to take the pump apart to check that. Some pumps will require removal while others have a quick clip arrangement to remove the pump portion from the power head.

If the pump is clear, the impeller blades are in good shape and it's getting electricity and not spinning, you need a new pump.