1. the door that opens in the middle of the cycle to release more dishwasher detergent doesn't open properly. Is there supposed to be a spring for it? I don't see one. 2. Is there a filter and if so, how do I find it? 3. When the dishwasher does run (when the door worked) ,the dishes were washed unevenly -- some get clean and some don't. I don't believe in replacing appliances unless it's absolutely necessary. Is there a way to save this? Thanks!