[cctalk] 3.5' 1.44 & 720K compatible Read/Write FDDs

Is there a list of floppy disk drives which could read and write both 3.5" 1.44mb and 720k diskettes? A product line of musical instruments (General Music/Ahlborn-Galanti) I service use 3.5" 720K DD floppy disk drives. I've never had any problems formatting or backing up data files prior on other instruments. Tuesday, I attempted to format a floppy disk using the instrument's internal FDD prior to backing up the data files. After the format an error appears "corrupted data". Which could mean so several different things from a bad floppy drive, etc. I currently have one box of Sony MFD-2DD 3.5" 720K Double Density Floppy diskettes which were bought new a few years ago, kept in their box, and stored in a dust free place. I've used them prior for the same purpose with no problems. I'd like to be able to verify at home that the diskettes haven't all suddenly gone bad. Thanks Don Resor