One of our BlueESC/T100 combos will no longer will turn on when connected to power (no lights, no PWM reaction). Reverse polarity is very unlikely as it has an XT60 soldered on the power input leads. Over voltage is also very unlikely, as we only ever connect them to 3s LiPos. It is seemingly spontaneous, as it did not break during use of the thruster, and there is no visible damage on the BlueESC circuit board (underneath the potting compound). What can be done to fix this?