I have a LG400 that I unlocked using a code that I bought on the internet. It has worked fine for a year. I was in service mode the other day and I don't know if I accidentally changed something or not. Now my phone works ok in 2G mode but doesn't appear to work in 3G mode or duel mode even though the signal strength is ok. It will connect occasionally in duel mode and 3G mode. Works great in 2G mode.
Does it hurt to do a factory reset? Does phone have to be re-activated with my unlock code if I do a reset? Will the reset do more harm than good? How about my screen picture? How about my address book? What is the factory default for modem/network/mode?
I have AT&T service.

See More: LG400 problem- Factory reset hurt anything?