LG LS770 no service issue

i have unlocked LG LS770 ZV8 then i used CDMA UIM it worked fine for two weeks , suddenly no signal ( service disabled or no service). i have tried re-unlocking the phone using GC pro but the same result …. i checked the following:
Baseband is fine.
IMEI is fine
MEID is fine and matching IMEI.
only PRL Version is not fine
PRL Version is 0…

i wrote PRL file again but the same issue still exist….
any solutions?