If this does not isolate the issue then this would
determine that the main flight board is the problem
meaning it will need replaced. Not very expensive, all
things considered, but a long, tedious and involved
process.
Note:
Be careful if you need to order a replacement esc or
motor (so far there seem to be two distinct versions of the
esc and motor) as they should all match ratings and
values otherwise there can be balancing and other issues
when you install a new but unmatched one.