how do you know they are demagnetized?
has the problem happened to all four motors? if not, you could take off the motor bell and put it onto another motor to see if the problem follows the bell or the windings,
how do you know they are demagnetized?
has the problem happened to all four motors? if not, you could take off the motor bell and put it onto another motor to see if the problem follows the bell or the windings,