No service on iphone 3g 8GB- please help

[ngwazi]

hey guys

i jail-broke my iphone 3g using redsn0w and everything worked well i can connect through wifi and all but it constantly has no service. Do you think this is a hardware or software problem, i have looked around to find people with the same problem and they have told me that all they needed to do was change the comm board and everything turned out fine. id like to know if anyone here knows how to fix this .thanks in advance to anyone who helps it would be much appreciated.

[i.Annie]

Did you install ultrasn0w...

[alvink83]

Yeah.... You need to install ultrasn0w from Cydia installer to unlock it first before you use your sim card.