Hi,

Can you hear the drain pump running when it should be draining?

If it sounds like the pump is running the first thing I would do is remove the drain hose from under the sink, maybe it connects to a food disposal and just look into the hose and connection for anything blocking the flow.

Also check the drain hose for kinks. If the drain hose has a splice or other connection anyway in the hose that is another spot they like to plug up.

If you can't hear the drain pump running I would check it with a multimeter for continuity. If it has no continuity then you need to replace the drain pump.