After resetting HTC Radar (w/ Windows Phone 7.8 on-board) to factory defaults it stopped working with 3G networks. Tried every possible way to solve the problem, ranging from changing SIM cards and to install a variety of stock and cutom ROMs and radiomodules. The only thing I could dig up, is that in the settings ##3282#, it is choosed using only 2G connection, when you change the settings on automatic or 3G connection visually appears H, then 3G, but in fact the network and all is lost, and when restarting the phone is reset to 2G connection again. 3G coverage is excellent, the situation is observed for different mobile operators / SIM-cards. Who are there views on this matter?
It may just be that the APN settings have got lost.
If you know what they are for your network, you can go to
cellular (assuming US English) and edit the APN in there