everything worked. thank you very much. May I ask for your help once more, how can I get the modem.img from another lgv30 phone to my phone? I am using lgv30 docomo up via rom lgmv300k in Korea now my phone is receiving the sim but no signal is on. Currently there is lg v30 docomo in operation normally.You are probably thinking of Master Reset, to stop the bootlooping. But if you are downgrading from Pie US998 to Oreo US998, there shouldn't be any bootlooping. HOWEVER, if you are crossflashing from another firmware like AT&T H931, Canada H933, Sprint LS998 to US998 Oreo KDA -- yes there will be bootlooping. For those you will need to follow the Frankenstein directions, where you downgrade to US998 Nougat. Run Master Reset to stop the bootlooping. THEN, you can update to early Oreo US999 for bootloader unlock.