Some times if yur mob didnt boot stuck in boot loop, sometimes it may cause by efs prob.if yu repair yur efs yur mob shud boot nd yur imei becom lik this 004999010640000. if yur imei 004999010640000 bcme lik tis yu can repair yur imei easily by software boxes (Z3X,OCTOPUS SPT ETC). yu can repair yur efs by octopus box put yur mob into download mode nd press repair efs aftr repair yu sud get tis imei 004999010640000 nd gud to reapir imei using z3x,octopus,spt etc.
How to repair efs with out box nd repair imei using z3x check below.
1)if yur mobile is null 1st download tis file N7100_repair_efs by gsm_anwar http://www.mediafire.com/download/t1..._gsm_anwar.zip
2) Put yur mobile into download mode nd run odin select the n7100 repair efs file into PDA nd flash it. aftr tat yur mob still has imei null factory reset nd check or update vit official firmware 4.1.1 or 4.1.2. still imei null yu have to use software box to repair efs to to get tis factory imei 004999010640000 i used octoplus to repair efs .aftr get tis imei i repaired vit z3x box .
3) Run samsung tool 16.1 i got error in latest version so i used 16.1 there 1st select the model n7100 nd pres read info (yu shoud enable use debugging b4 doing tis) if yur mob not found press read info again it should detect nd read the mobile.
|ote:now samsung tool 18 available there yu can repair directly vit out uart cable|
5) check imei repair option nd write down yur imei nd press ok while doing its process it vil ask to cnnt uart cable dissconnt the usb nd cnnt the usb if all went successfully yu vil get yur imei .
6) If yu get Bypass MSL... error do it agin . use 510 k uart cabe .