Sounds like a moisture problem alright I had several of the LED Strip lights and they all died the same way.
I also have one of the 48-60 fixtures that quit on me. I went through 2 power supplies in a little over a year. I finally put one of the 5 amp led power supplies you can buy for LED strip lighting on it and it has been fine since.
Why would a company make lights for an aquarium that are not water proof, even with a glass lid there is still a lot of moisture around the fixture and I suspect my fixture will go the same way as the LED strip lights in time.
I have a glass lid but there are 10 other tanks in the room so a lot of moisture too. . I love the fixtures but I don't think I would buy any more of them.
Current needs to give their head a shake, and make their products water proof not just water resistant.