hi hyperion17,

thank for your answer.

before i flashed my k610 it had r1gb001 firmware and it had gsm 850/1800/1900 and utsm 2100.

after i flashed it to a newer firmware, r1jc002, it become gsm 900/1800/1900 and utsm 2100.

now i got a new sim that's work on gsm 850 so i need to get back the gsm 850 but i don't know how.

can you help me do that?

thanks.