Samsung s3 i9300 Serial Number repair issuee, need some tips

[gsmro2012]

i have an s3 with 0049 imei an zero serial number.
i've tried to repair both but gives me error, so i repaired imei first this action reported succes i get signal can make and receive calls.
but when i try to repair the s\n it gives me msl bypass error or if it succeds the imei becomes 0049.
this means that i have damaged efs? because i don't have any efs backup.
any ideas on how to solve this problem the customers wants me to repair both imei and serial number.

another thing the customers went to another service where he got the imei and serial numer fixed but the phone didn't get signal. he told me that they used spt box. after getting his serial and number fixed he came back to me to write again the imei in order to get signal, but the sn got zero again.

[45069]

search in this forum you wil find answer, today i managed same problem,