I find it tricky to sell broken stuff. I usually claim that my "wonky" item is only for parts or repair. That way it is totally clear that the item is not working right. I put it in the title, use "for parts or repair" as the condition, and I put the issues up-front in the description.
I find this particularly important with electronics. Electronics that are partially broken can be really challenging to assess. Why did it stop working properly? Are you sure that the remaining functional part will still function for a reasonable amount of time? If I can't assess it, my approach as a seller is to "shoot low" and "be pessimistic".
You can, of course, be an optimist and claim that it is a good item with some flaws. But in that case you should expect more claims for refund. I see many sellers list items that need repair as "used". In my experience, this is an approach that will lead to more unhappy customers and therefore more returns that are harder to fight. I know I've bought "used" items and sucessfully challenged the seller when the item was significantly less than noted in the tone of their descritpion.
Using my pessimistic strategy, I find that buyers can still make the mistake of buying an item that they don't really want, and demanding to return it. But I found that eBay hasn't sided with them.
