Yes, it sounds like the YSus died; the IPM most likely is shot. Generally, it's recommended that both ZSus and YSus IPMs be replaced at the same time because of similar wear rates. If you're going to buy a used YSus, definitely go back to ShopJimmy to make a purchase to take advantage of the warranty protection they offer.
If you're adventurous...not an easy fix without a desoldering gun (e.g. Hakko 808):
https://www.youtube.com/watch?v=Y8MNQYXw8E0