How do you turn off the "Auto Power Off" feature?

WK-3000, WK-3100, WK-3500

Auto Power Off will turn the keyboard off after 6 minutes if it is idle and not using the AC Adapter. To turn this feature off, please use the following steps:

Hold down the Tone Button while turning on the keyboard.

The next time the keyboard is powered off and back on, this function will be re-enabled.