How to Disable 3G on your phone to save battery life.

I have a newer 3g chip, as I got my Impression in september 09. It seems that when you make the changes and you save, the changes don't take efect. It would make sense as to the fact that the phone would already had connected to a 3G network. You need to go into an area that forces the phone to look for another network, or the easy way would be to power cycle your device (turn off the device, take the battery out and wait about 30. Then put the battery back into the phone and turn on the devce.) It seemed to work for me.

Also another thing you would like to try is going to 3: network & call settings, 5: service domain. This, combined with the earliest steps of turning off 3G, would in fact turn off EDGE when is not in use. You would see the E for EDGE on your screen per say when your using the internet, but when you exit the internet it would show for about 10 seconds and then it would dissapear. To use the internet again, just open any program that requires internet, and it would connect to the network again. Notice we're talking about DATA and not the voice part of your phone, so although it wouldn't be conected to the EDGE network (meaning the device is not requesting or receiving any DATA), it would still be conected to the towers so you could make and recieve calls. Any questions feel free to ask.

so how do you turn on 3g back again?

I tried newguys method on turning off 3g and so far it works perfect where at first i didn't have the network mode option after changing the UIM class and rebooting, it appeared. Thanks for the info. i have a question, in network mode there are many gsm options:

(gsm only, gsm 850, gsm 900, gsm 1800, gsm 1900, gsm 850/1900, and gsm 900/1800)

I just chose gsm only but what exactly does the numbers mean and what difference will it make choosing them? Thanks

 ( What are the default factory settings? ) I changed my settings to disable 3G and it works great. Did not pay attention to what they were before the change. My carrier has recently upgraded in my area and I would like to try 3G, never had it before that's why I disabled it.

how come my phone only connects to edge?
i've never seen it ever connect to 3g..

Never mind.  I finally got it.  Won't be trying that again. LOL

Thanks newguy!!!!!!!  Worked.