To maintain the data stored in PSR630 memory, a live power source (either batteries or an AC adaptor) must be connected to the unit at all times.
Data can be maintained by using just one type of power source, but there are drawbacks. If using only an AC adaptor, it must be plugged in to a live AC outlet at all times, even when the unit is off. With this setup, the keyboard could not be moved, because it would have to be unplugged, causing all data to be lost. Also, if there is a "power outage" or tripped circuit breaker, the AC outlet will go "dead", causing all data to be lost.
If only batteries are used as a power source, the unit can be moved without fear of losing data. However, when the batteries expire, or when they are changed, the power source is temporarily removed, and the data is lost.
For these reasons it is recommended that both an AC adaptor and batteries be used to maintain stored data while enjoying the freedom of using the keyboard anywhere.
CAUTION: Stored data can still be lost when using both batteries and an AC adapter. If power is turned off to the AC adapter before the DC connector is removed from the unit, the data in memory will be lost. Always unplug the DC power connector from the PSR630 unplugging the AC adapter from the AC outlet.
To avoid accidental data loss when using both batteries and an AC adapter, use the detailed POWER UP and POWER DOWN procedures. POWER UP:
1) Plug the AC Adapter into the wall.
2) Plug the power connector into the PSR630.
3) Press the [STAND BY/ON] button on the PSR630 (the button is down when in the ON position).
POWER DOWN:1) Make sure batteries are properly installed.
2) Press the [STAND BY/ON] button on the PSR630, turning the power off.
3) Unplug the power connector from the PSR630.
4) Unplug the AC Adapter from the wall.
Reference: PSR630 Owner's Manual, p. 152