A method for off track prediction comprises predicting a position error signal of a write head, comparing the predicted PES to an adaptive threshold, and preventing a write operation of the write head if the predicted PES exceeds the adaptive threshold. An opening of the electronic device enclosure provides access to electronic componentry. A pair of switches may be mounted in separate locations to detect the position of a control arm used to rotate the trunnion arm. The technique includes similarly determining a relative ending phase of the input signal at the end of the period.