Mosfet connection probably went, if its under warranty send it back to your supplier, if not throw it in the trash. If your using LR Atty's try not to chain vape with your Ego and get them real Hot, where the Atty meets the Batt the Mosfet connection blows once it gets to hot, so in other words don't chain vape as much, give it a bit in between vapes, it's better to get the higher mAh Ego's too if your using LR Atty's. Remember these are only
batteries, not much different than any other and they do go bad and only last for so long as well. You may also want to think about getting a
mod with some stronger Battery power that will hold an AW IMR Batt. I have probably 30 Ego's and have only had about 4-5 go bad on me so far since there inception but I dont use them everyday but when I did these few went bad from using them hard with LR's.