Someone was looking for this - got it from KYO today:

1) Remove the battery from the phone
2) Press the reset button (located on the top right of where the battery was located)
[NOTE:] You may wish to place the battery in the secondary charger on the cradle to make sure it has a full charge; this can take up to four hours
3) Hold down the reset button for one minute

Before setting the battery in the phone, please plug the AC power adapter directly to the bottom of the SmartPhone to see if it will power up.

4) Set the battery back in the phone
5) Perform the steps below to perform a Hard Reset

How Do I Perform a Hard Reset?

6) Please test your device, without performing a HotSync. If the issue does not persist, it may be software that is transferred to the phone during a HotSync causing the issue.
7) HotSync your SmartPhone to retrieve your information
Test the SmartPhone after performing a HotSync to see if the issue returns.