I have a Garrett BFO detector that I bought in, I believe, 1974. It was the first discriminator that Garrett came out with. I haven't used it in about 5 years and when I put in new batteries it doesn't work any more. It hadn't been stored with any batteries in it. I know this is an out dated machine but I use in it in about 3 feet or less of fresh water looking for, mainly, rings. Anyone know of a place that works on these older detectors? Called Garrett, they don't work on these older units.