hello everyone. i need help on my xperia. last time my fren help me flash the rom to another one called pctech4u. now i wanna flash it back to the original factory rom. how do i do that? hard reset doesnt work and SE service center cant do it. HELP!!

yeah which 1? there are 2 links. and how do i install it in?

Hello, i own this phone since it first launch and i have some problems wondering you guys can help me solve it. My friend helped me to flash the phone to a HTC custom rom but now i want to flash it back to the original factory rom. Hard reset doesnt work and sony ericsson center say they cant do it as well. Some phone shops in pertama complex gave me the same excuse. Can anyone teach/help me to restore everything back to its original form?

Im not really sure what rom is it? How do i check it?