Sent my f5 to FT for crazy id's on low conductors. Daniel called me and said he had tested it and it was working like it was supposed to, nothing wrong. I mentioned the pin point fading away sometimes. He said he would check it. Got it back Friday .Went out 2 hours Friday 4 hours on sat and again today. It is a completely different machine now.Id's nickels in my test bed with solid id at 5 inches. Dug 2 nickels today and showed solid id of 30 .The gold ring that bounced from 25 to the 70's now locks in an id of 28 to 30 at 4 inches . Even the volume is much louder ,have to use an in line volume control . Hat's off to Daniel at FT He was concerned enough to call me and not just write me off.I am impressed once again with FT customer service.Love my detector most sensitive I've ever used.