ge dishwsher not draining

I have a ge dishwasher that will not drain. I started off by cleaning out the machine, the motor is getting power checked with multiumeter, the drain sylinoid is engaging when running. replaced the filler ball wasmissing. All hoses are cleared of clogs, took off drain hose and ran water from outide hose through the drain hose. checked motor impeller is running fine. I have taken apart the all the hoses and check for clogs and is still not draining, what have i missed.