Our 8 year old integrated

Question

Our 8 year old integrated 2 draw dishwasher (top draw) has a problem on the rinse cycle and constantly beeps and water at the bottom of the draw remains. I have cleaned out all the grit and stuff residual water and tried to use again. But alas there appears to be a blockage still on the rinse cycle. Can you help or do I need to get a plumber?Thanks...Louise