I've had a MH27 for about 2 years, and this will be the 4th or 5th time I've had to replace it. Ridiculous right?? I hope they still honor their warranty. Obviously I've done the normal troubleshooting, but again there's something wrong with the electronics and the soldering. This is why I love my Zebralights. They never fail and I have a lot of confidence in how they're built. My next light will be a weapon light, probably a Malkoff or Elzetta. I guess what I'm saying is buy a good quality light in the first place even if it costs a little more.