my zanussi dishwasher flashes code a7 and makes a humming sound when first started on a program but if you pull it out and tip it back it will start program as normal filling up washing ect but after a short time into the program will stop and flash code a7 and if you try and restart it by holding in the start button will make a buzzing sound and is there a program on this dishwasher to tell you what the fault is the make and model no are zanussi aquasave plus dw 930