Thumbs up [Q] network not registered

when im on gsm mode, my phone registered on network. but when i switched on wcdma only my phone say theres say
'emergency calls only" not registered to network. its not a simcard problem because when i insert my simcard to my xperia its work fine bot gsm and wcdma. my imei was fine. i have tried all to fix this, updating firmware wont fix this. is this a modem file problem? kernel problem? broken efs problem ? baseband problem or what? please helllpppppp