how to fix no service iphone 3gs

what EXACTLY is the "no service problem"?

Hi, I've the same issue with my 3Gs, after my update to 5.01 I've had signal problems

It either says searching or no service, I've taken the sim out cleaned it, I've reset network settings

But I'm at a loss as to what's wrong!!!

i updated iphone 3gs from 4.1 to 5.1.1 and em facing the same issue with my 3gs.. what i noticed is if 3g is activated on your sim then single network bar signal is displaying and you can use your phone.(for calls and msgs)

go to settings ,network and turn on only 3g its actually helped me. but i am able to use only airtel carrier service.

one more thing if i am at home only 1 signal bar is displaying and if em out 2,3 bars is been displayed.

*NOTE you have to turn on only 3g from network and 3g should be activated on your no.

my iphone is factory unlocked and still am facing such issue:-/

i have same problem i can try to update but no sucess