Turn it on and hold the barrel firmly sir that the cable doesn’t move, then wiggle, if that breaks power then it’s your board
if you plug the cable in and wiggle the cable ever so gently and that stops power then it’s your lead - this would not surprise me, firstly it’s super short and easy to get taught, although it has good strain relief, so if it was taught it could do something to the board I guess
also look at far end of cable near plug for evidence of issues
info required here