root your phone and
try this *#7284# and choice USB
reboot
choose samsung usb diag com port

and read code or direct unlock

-------------------------------



Reading Phone Info... OK
Model: GT-B7510
Country Code: SFR
Cal Date: 2011-07-13
Factory SW: B7510XWKG2_SFRKG2
Unique Number: ******************
Memory Phone: KAT007012B(B7510)
Phone S/N: RUQB797575
Build: M76XX-TSNCJOLYM-60501005
IMEI: ****************
PDA/CSC Version: B7510XWKG2/B7510SFRKG2
Phone version: B7510XXKC3
Phone HW: MP 0.500
Cal Date: 2011.07.30
Read Security... OK
Bypass MSL... OK
Reading Codes... OK
MCK: 47471571
NCK: 05838262
NSCK: 00000000
SPCK: 00000000
CPCK: 00000000
Done with Samsung Tool ver 10.5