the glasses are cloudy, nothing is clean?

hello, I have just moved into a house with a diplomat dishwasher - exciting, until i discovered that it doesn't really work. the soap is still lying at the bottom of the machine and nothing is clean. I have cleaned the filters, put a whole bag of salt, filled it with rinse aid but it hasn't made any difference.
Can anyone help - i would hate to have to call an engineer... thank you.