You must flash your phone with these files:
K770_R8BC004_MAIN_GENERIC_VI_RED52
K770_R8BC004_FS_EUROPE_5_RED52
HB1-06_Gen_CDA102568_14_R8A_GENERIC_EUROPE_5
If you have EROM CID53 must use these:
K770_R8BC004_MAIN_GENERIC_VI_RED53
K770_R8BC004_FS_EUROPE_5_RED53
HB1-06_Gen_CDA102568_14_R8A_GENERIC_EUROPE_5