there are too many ways for people to go wrong during their development.
i don't see how we could give examples without creating bad stereotypes.
its often the relatively saner/less stuck people, who admit a psychological diagnosis or allow their "lack of balance" to become apparent, as they try to learn from it. they would ask for therapy all the time, while the biggest nutcases refuse any questioning of their sanity as insulting lie.
if i would describe the most nutty version of a type, it would offend the above group. if i would describe the above group of a type, it would be harder to see a simple correlation with the function model (since they have more depth and thus are more complicated ...).
in anyway, psychological imbalance should not be interpreted as the result of a technical imbalance of functions, like some kind or hormonal disorder. it might be related in how it unfolds in terms of symptoms, but again, that is a too broad topic.
or do you want to define the word balance in a strictly typological way?
in my eyes, that would be two different topics.
you may have heard before that infj are supposed to struggle with the different worlds of sensing and intuition, while infp are supposed to struggle with the difference of thinking and feeling. or was it the other way round?
i believe i have observed that dominant Ne types can have trouble with the "rhythm" of everyday live.
stuff like that is about technical balance, but not related to psychological balance.
psychological balance is for example something like self-destruction ... such things are rather related to the content or style or character of functions, not their "strength", but ultimately they are motivated and thus very individual and should be explained by psychology, not type)
so lets try to separate the two sorts of imbalance by careful abstraction.