Pretty much any piece of gear that has memory capabilites uses an internal battery for powering its memory when the AC power switch is turned off. Most of these batteries have an expected life of 5-7 years. Here in Sweetwater’s Service Department, we’re seeing the batteries in many older keyboards are starting to fail, often resulting in permanently lost or scrambled data. You should consider having the battery replaced in any gear made before 1991 or 1992. In keyboards, this includes the Korg M1 and Wavestation families, the Roland D-Series family (D50, etc.), Yamaha DX7 and extended family, Kurzweil K250 and K1000, and many others.
Corollary To Today’s Tip – We’ve said it before (and we probably will again): It is essential for every electronic musician and studio owner to perform regular backups of any volatile storage media. Hard drives are the first things that come to mind when talking backup, but battery-backed RAM certainly qualifies!