My Eotech failed after 2 years because of contact oxidation.
I saw 2 videos on youtube saying that this is a very common failure and Eotech supports it under the warranty.
https://www.youtube.com/watch?v=u25_YzqYrA0
https://www.youtube.com/watch?v=_8Ob5-HObK4I wrote to John and he sent to me the repair kit at no cost with express post.
Best service ever.
Thank you to Mr. Wolverine