remove the board, check that the on/off middle button is not sticking. if it continues it could be a processor short, as mine was. sent back to eclipse and they replaced it. top service from them.
Scrub the board with IPA(100%) and a toothbrush(gently). Squirt some into the switch and turn on/off with no battery in. Leave to dry somewhere warm for 1-2 hours.
Had the same problem and it was the middle button had moved slughtly in the groove it sits in on the frame so would not depress properly. Remove the grips and board and check the buttons are all flush then re-assemble and see if it works