electric brake fix ?

my JCB hedge trimmer model is fitted with a electric brake device to the motor ,when you release the trigger the blades used to stop almost instantly,this function has now stopped working and the blades now run on for a fair bit before stopping (no braking effect )

how do i cure the electrical braking to to the motor problem, is the capacitor across the switch the problem or is it there to prevent arcing on the switch contacts

dave
June 2010