The very best advise here so far is call Ranger. You'll be amazed at what they will do. First owner, second, third - doesn't matter. However, the way to fix them is to get a pop-rivet gun and an assortment of aluminum rivets. The hinges on my 520, and my son's 519 are screwed to the boat, and riveted to the lids. They are hollow, and because how a rivet works, it expands from the back side (inside the lid) and from the front to tighten. I've had a few get loose, and the rivets work just fine. Do yourself a favor, and get a quality rivet gun. A cheap one is frustrating, and doesn't grip to pull tight, and make tight connections. Also, besure to cut the old rivets out before you replace them. Hope this helps,
Total Recreation Products Inc.
Commercial Park and Playground Products and Services
Ranger Z520 250ProXS