My dishwasher detergent dispenser cup does not open...

• Check the dispenser cup for debris and old detergent build-up. This may prevent the cup from opening properly to dispense the dishwasher detergent.
• If your unit uses a bi-metal switch operated by a timer, if the bi-metal switch is faulty, the cup will not open to dispense the detergent.
• The dishwasher timer assembly controls the sequence of the dishwasher cycle. A faulty timer will make the detergent cup dispenser open intermittently. Call a professional appliance repairman to service the unit.