One possible problem is a clogged solenoid valve. This is the device the water supply line is connected to. To check this will take about an hour and few tools (screwdriver, small adjustable wrench, pliers or channel locks, teflon tape). Switch off the breaker to the dishwasher. Turn off the water supply and remove the cover at the bottom of the dishwasher. The solenoid valve should be visible at the left side. Disconnect the water line, the rubber hose, and the wiring connector (note which color wire is on top). Remove the two screws holding the valve to the frame. The valve most likely has an elbow fitting where the water line was attached and it needs to be removed (don't damage the threads).
Now you will be able to see the screen filter inside the valve. If there is debris in the cavity where the screen is located this may be the problem. If there is no debris reinstall the valve and reply back/repost. Remove any debris that is in the cavity. You can pick around the screen with a large straight pin to dislodge debris but don't do any damage to the screen. Partially fill the cavity with water (just over the screen), hold thumb over opening, and with thumb pointing down shake valve up and down several times vigorously. With your thumb remaining in the downward position, release the water over a sink or container and repeat process until no debris is evident. Reattach the elbow fitting using 2-3 full wraps of teflon tape on the threads that attach to the valve (not where the water line attaches), tighten fitting adequately using a wrench and ensure fitting is pointing in the correct direction to easily reconnect with water line. Reinstall the solenoid valve to dishwasher frame. If the water supply line is copper and it does not go straight into the opening of the elbow fitting, carefully bend it so it is aligned with the opening (don't bend it too much in one place or within 3 or 4 inches of the end). Attach water line and tighten snuggly, but not over tight. Turn water supply on, check for any leaks, and tighten more if required (one-eighth to one-quarter turn at a time and recheck for leaks). Attach wiring (proper color to the top) and rubber hose and secure hose with its clamp. Switch breaker on and begin cycle on dishwasher. While washer is filling check for any water leaks. If everything is OK, replace the lower cover. I hope this fixes your problem.
Glen
November 2005