Are you tired of opening the dishwasher to find it's full of dirty dishwater? Your first thought might be that you have to replace it or have it repaired. Either way, it means a considerable expense.
But what if it's not the dishwasher? It could be that you have a plumbing problem that has nothing to do with the dishwasher at all. The water has to go somewhere, so a blockage at any point from the dishwasher to the drain can be causing the problem. Something as simple as a clogged air gap can keep the dishwasher from draining properly.
Before you consider replacing it, check for possible plumbing issues that can lead to a dishwasher not draining properly.