Think I've posted this before some where. Make sure you test box and cover out side your house as all sorts of electrical stuff upsets the box, TV's, Florescent tubes, you will be surprised. If out side wire mesh galvanised sheets also upset them etc.
This might help remove the battery take the insides out of the box remove the screw from the centre of the depth wheel, remove the depth wheel. Then remove the thin plastic cover usually yellow or white. Now carefully clean the Carbon horse shoe shape resistor with a cotton bud and little Isoclene or Mentholated spirt. Make sure your batter