After a great Christmas season and show, yesterday I noticed that one of 4 of the 27 ch controllers was acting up, last one on a set of 4. It started out great and then with in 3 hours the half of the tree, it was controlling, just stopped. I opened the box and noticed light was just flashing, no signal of course. But it slowly lost signal. other 3 work great. Is there something that could just slowly fail on these?