Hello,
If you hear the dishwasher motor trying to go during drain but all you hear is a hum, it sounds like you may have something stuck in the impeller preventing the motor from going. If you kept the motor on while its humming, it will heat up and then shut off on its overload switch. Do or did you hear any grinding noise prior to it not draining? A piece of glass or anything could get in there and cause this. Hope this helps.
JP, February 2006