Iphone 4 no service problem?

I have a jailbroken iphone 4 with 4.12.05 baseband and even though the iphone doesn't have a simlock it still doesn't get service. How do I fix this?

First thing is that it may be reported lost or stolen making the service provider block it. This can't be unlocked but can be used abroad. Another reason it that your phone may be water damaged or not yet activated. I suggest you take it to apple or where you got it from to make sure nothing's wrong