Did you attempt my method?
I cant see how you can update prl/profile without a signal. couldve told u that wouldnt work.
Try what ive posted above if you didnt already
If that dont work you need to reflash the stock rom (http://forum.xda-developers.com/show....php?t=1904099) and do the ##72786# trick
Man, I tried the ##72786# and I get the following message:
Connection Problem or invalid MMI code
I'm loosing signal, when I try to call it doesn't complete the call and even with my S3 showing signal when I call to it's on the mail box...
I lost signal after flash a custom rom. I tried to get back to the original twice, full wipe and stuff but nothing... signal keeps dropping...