Prentke Romich Company
http://www.prentrom.com/support/article/333

How do I Reset my Liberator - Power Failure Recovery Code - Error.

If your Liberator is displaying the message "Power Failure Recovery Code Entered" or if the device is frozen or will not respond, perform the following reset:

  1. Unscrew the battery pack screw one half turn counter-clockwise.
  2. Slide the battery pack out until you see the battery telephone cable.
  3. Unplug the battery cable.
  4. Plug the battery charger into the battery pack.
  5. On your device, hold down the OFF button .
  6. As you are holding the OFF button, plug the battery telephone cable
    back in. DO NOT let go of the OFF button.
  7. As you are holding the OFF button, push the ON button as well.
  8. In about 10 seconds you will hear a beep.
  9. When you hear the beep let go of the OFF button and then release the ON button. 
  10. Watch the screen, the Liberator should power up normally and show
    "System is Ready for Use. "

    Check the battery status.  If it is NOT close to 100%, charge it right away. The Power Failure error was displayed  because the battery went to zero power. The device memory should not have been erased, and doing this procedure will NOT erase your memory either.

Note:  If this does not resolve the problem, you may want to try a 6 beep reset.  This will result in ALL vocabulary being erased but it may be your last hope for getting your device up and running without service. 

To perform a 6 beep reset follow steps 1 - 8 above but do not release the OFF and ON buttons after the first beep, continue to hold for six full beeps, then release.  You will then see a message "Warning: continuing with reset will result in all vocabulary being erased.  Press ON to continue."  Press the ON button to hear 3 long beeps.  Now the device should be operable and ready for you to reload your vocabulary into the device.