Ok so i got brave and plugged a battery to towerto see what would happen i connected to beta flight to see if motors would work i knew 1 probably would not because it smelled burnt and i found three would spin up but the burnt one would not so is the motor bad or motor and tower are bad or is tower and all motors are bad?
if you have a worn but working motor solder onto none working esc pads to see if spins, if spins motor bad if not esc bad.
you could just swap motor on quad around but if esc bad could take good motor out, (doesn’t normally though)