i'm sure it's been answered--

my treo 600 when not plugged in to the charger goes to "no service" when making calls...

i heard sometimes i need to call sprint and they'll reset my phone on the network... and i heard sometimes this same issue is a hardware issue.

how can i fix this?

and ha, if i do need to go mess witht he battery and stuff... hwo do i unscrew those tiny little screws in there... i only have philips and flathead.