I have seen
Se vende solo por renovación on lots of sites similar to ebay.
What does this mean? Does it mean the product needs to be repaired?
This is Chilean spanish, if that matters.
Like others mentioned before, it means the owner is selling the item because he or she got a better one. This is the usual case when you purchase a new phone while your current one is already working. You put it on sale and remark that you are selling it because you got a newer and better one, and not because it has any defect or is not working, so potential buyers feel more confident.