I just moved into a new (old) farmhouse and found a bunch of corded and cordless power tools of various ages and operability in the barn. One thing I found was a cordless Dewalt DW972 drill with four battery packs and the charger. The drill doesn't work after charging all the batteries and inserting them. Is there a way to tell if it's the batteries that are shot, the drill or both, without buying anything? I already own a 5-year old Ridgid 14V cordless that I love, but it can be a bit heavy with extended use, so the Dewalt would be nice if I can get it to work on the cheap. Thanks.