Q. My bird smells. It never did before. The cage is clean. I see no sores or anything and her feathers aren't falling off. What's the problem?
A. Things to check for would be a mouth lesion or any wounds under the wing, although this would be unlikely.
Another possibility would be what is called a gatroenteritis (upset stomach and gi tract) caused by clostridium or yeast.
Dietary changes or feeding the bird table food - mainly fruits (bananas, oranges) - can cause the droppings to smell more and the odor can linger.
I would recommend having your bird examined by someone who has a good knowledge of birds.