I have a Tungsten T3

I have a Tungsten T3 that was originally purchased in
2005. After much heart ache in the beginning I have had a very dependable
device until today. The T3 was working normally. I added a calendar event,
turned the device off and walked across the building. When I tried to start
it up again and use the device the screen was/is dark. I placed it in the
cradle and the charge indicator comes on. I let it charge for 15 minutes
then tried a soft reset. No dice. Then I put the speaker to my ear and I can
hear a faint siren sound (like an emergency vehicle siren). I then tried a
hard reset. No change in operation nor has the sound changed or gone away. I
have heard that opening the device and unplugging the battery may cause the
unit to reset and come back to life. Any thoughts on what to do?