Hello, i have a friend that has a tesoro vaquero, great machine and deep, buy lately hi has been having trouble, he told me that when he finds a target the vaqueros response when detecting a target is late, for example when the coil passes above the target , when it was working well it beeped immediately and now that beep comes about one second later and he has been struggling , he has been taking a lot of garbage, and hi also told me that the ground balance button gets it down , before it didnt happend........i hope you can tell what could that be thanks