L&M Repair
Just an update - L&M repaired my two Taz lights and they work great. They did let me know the recent lights have updated firmware that they loaded this update on mine. No root cause on failure, but I suspect their mentioning this indicated it was part of it. None of their single LED lights have failed me, only those with self contained battery + multiple LED in the head (sorry if I wrote this in a way that confused - only 2/4 of my bar mounted lights have failed). Online it looks like quite a few others had issues with Taz lights just stopping as well, but what I can say is that their customer service is amazing and their repair appears solid. I'm hoping the firmware update resolves all issues and they work both for me and for you if you bought the 2k lumen (I have 1200 and 1500). Still the best beam pattern for a handlebar mounted light by far. Happy riding!