Is there any way to identify the original carrier of note 2?

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http://forum.xda-developers.com – I bought a second-hand note 2 on ebay, this guy tell me it's rogers phone, but it requires unlock code when i put in my rogers sim card. So i figured that this is not a rogers phone, and i need to unlock it. The problem is that, i can't get contact to the seller, and buy an unlock code on ebay requires information about the original carrier, or it will cost like $40. There is no carrier's boot up logo, nor carrier's custom apps, so is there any way i can identify the carrier? Thanks! (HowTos)