If your m125 does not even power up with fresh batteries, it sounds like the device is shot.  Is this device new to you?  Has it ever worked for you?  Only thing I can suggest is pressing the Reset button in the back for a Soft Reset, or trying a Hard Reset.  If it doesn't start then, there is a hardware problem.

This article discusses the various types of Reset for different Palm devices:

http://tinyurl.com/zlwza