No service after unlocking iPhone 3GS PLEASE HELP ME!

[cheerrock96]

Ok so I have my friends old AT&T iPhone 3GS 16gb. Anyway I jailbroken and unlocked on redsnow(I think) and I went to cydia an downloaded ultrasnow and It will like once every 15 min pick up my tmobile simcard but I only get one bar. Does anyone know how to make me get a decent signal ?

 

[Applejuiced]

Turn off 3G in settings.

 

[Kwa Sein]

need activation

1 You must need activate ur phone after firmware restore or new device
2 need U check network if U carrier logo is only stay with searching