What version of the ESC do you have? Is the heat sink glued to the heat shrink tubing? If so, you have one of their poorly designed units and just another BEC probably won't fix the problem. The electrical shielding on these is ungrounded and very susceptible to electrical noise, which can result in unexpected cutoffs for a fraction of a second. Also, they tend to overheat. I just "redesigned" my Align 35A, and it has stopped giving me problems. If you have the bad version, I can give you more details on what I and others have done.