yah, i couldnt find tmobile setting on att phone bb 8320. but getting the escreen up was tricky. you gotta use the uptime thats showing on the help screen. without exiting the screen or changing it. make sure you use the alt key to type numbers, and dont worry to capitalize the letters. if it doesnt work, back out of the homescreen and reenter it. you will have a different uptime, and the esceen code calculator gives a different code.
now, if someone can figure out how i can edit that last setting, adding in the tmobile segw cert. or what i could use for O2, which is on at&t. i have a feelin this aint gonna happen. at&t dont got the stucture for it or something. but who knows what they dont tell us.
i punched in the escreen code on a world edition bb 8330. everyone agrees this phone has only non-USA gms capabilities. just CDMA here in usa. but i found a reference to it having all but 800mhz. found it in the esceen. there is alot in there
i also found a secret screen on a crashed bb 8220. instead of the usual JVM error and reset, it had other options. i aint got that phone no more, so cant document it.