Dishwasher won't drain at all. I have cleaned all the filters, taken the sump assembly apart, lower tub filter and taken everything apart underneath to clean it all out. Still won't drain.

Tried pulling the lower spray arm off to create pressure difference. No drain.

I can hear the pump humming, but it won't move the water. When I pull the drain line apart below the unit, I can get the tub to drain out completely.

Please help! Is this a bad pump? Buy a new dishwasher?