2 months. And It died. My guess is ''maybe'' juice got in it. I dont know. Where I bought mine there is many comments where other people had to replace it. SO it isn't just mine that had issues. They must have gotten a funky bunch!How long did you have your M80 before it died? I have had mine now for about 2 weeks with no problems. I hope it holds up. For a 80watt device, it sells at a good price.