there are several options which can be the reason for a not working magnet
  1. Does the countdown start?---If not the problem is caused by defective magnetic switch/ release button unit!
  2. Does the red release button stuck in its framing and cannot be activated-- the release button needs to be changed!
  3. Release button is working, countdown is starting!-- The magnet itself is defective or the wires are no longer connected to the plug!