Hey guys I have 2 mk2 boxes used them 2 years ago in and around leci fences and pillions ever since the dept have gone way off I can add new batteries and it will work fine but then after 2/3 mins it's goes all funny and won't pick the collar up unless your 1foot away and even then it's says it's 8fy away any advice this is both boxes so is this likely to be the collar or boxes cheers