Hello, we bought this model about 5 years ago and it hasn't really been used much. Recently it was left on for several days and when my husband went to use it he couldn't get it to change modes or even turn it off. He unplugged and tried again a few days later and while it worked he wasn't able to change the mode from the program my daughter uses. As of today it won't work again...it just says "select program" but won't do anything. Can you tell me what kind of service it might require? Thank you.