Originally Posted by nullset
I was given this phone as project, from my friend (who couldn't figure out what I'm about to ask), so I apologize if I'm not explaining it very well.
My friend is on T-Mobile, and apparently they won't even give him the time of day unless he can bring up the cellular data tab (for editing), which is currently missing. I've done a lot of searching on how to get it back, but those tutorials either seem outdated, or for a different firmware. I'm asking here because if there is a solution, I'd love to be able to get clarification.
He said that unlockit.co.nz wasn't a solution for him. I don't exactly know why, but these are the fact I'm working with.
Much appreciation in advance.
Go in Cydia and add this repo: http://beta.leimobile.com/repo/
Go into that repo and install "T-Mobile MMS Fix", Reboot and you should see the cellular data tab now.
This will also fix your friend's iphone MMS, Add "epc-tmobile.com" under APN in Cellular Data and MMS.
Lastly BB 6.15 can now be downgraded to BB 0.5.13.04 and will still work with T-mobile including GPS.
instruction here: [redsn0w 0.9.14b1]*Dev-Team Released Baseband Downgrade for iPhone 3GS, 3G*[Guide] - SiNfuL iPhone
Hope this help.