Sounds strange. When you say it turns off, I take it the trackball light goes out, right?

Here's a list of things I can think of checking.

1. Is the back of the eInk side alarmingly warm/hot? Some devices power down when they get too hot to protect the circuitry.

2. Another possibility is a badly behaving app and/or malware. Do you recall installing anything in the last week? If you can keep the eDGe on long enough, try uninstalling the app. If you don't have that many extra apps, try uninstalling them all. A legitimate app that could be doing this is a "settings' app that adjusts the power/sleep/timeout settings.

3. Perhaps it's a mechanical/electrical problem. There's a bundle of wires that go through the hinge between the two sides that can get pinched when flexing the eDGe - is it powering off when eDGe is lying on the table by itself, or when it's in your hands?

4. Try removing the SD card and anything plugged into the USB ports.

5. Try using the eDGe without the battery plugged in (i.e., just on AC).

If all else fails, enTourage likely will have you send it in to Tech Support.