Many dishwashers are built underneath a counter top and are therefore hard to work on. Normally a plumber is required for most repairs, but the drain can be checked for clogs easily and fixed without professional help. If you have no idea how to use hand tools, such as a screwdriver, it's recommended that a plumber be consulted and you do not attempt any repairs on your own.
Locate the drain hose that leads to your garbage disposal. To unclog it, turn off the electric supply, remove it from the disposal and run one end of a metal coat hanger through it from end to end. Move it around well, and pull the clog out if it's present in the hose. If there's no clog present, hook the hose back up to the disposal.
Look through your dishwasher manual to find out where the drain is located. This will give detailed instructions on how to remove and replace the drain catch as well as any filters that are located inside. This differs from brand to brand and year to year.
Clean out the bottom of the inside of the dishwasher with your hand. Remove any food or debris that has built up on the bottom.
Place baking soda into the drain and then add vinegar. The chemical reaction between the two will cause a fizz and this will break up any leftover food or hair and other debris.