iPhone 4 stuck on searching for signal

[solerblaster]

My Iphone 4 is stick on searching signal and I have tried turning airplane mode off and on, cleaning the sim card and restarting the phone, but it is still stuck on searching.
additional information:sometimes it says no service, I recently restored the iphone 4 to remove jailbreak, service provider is t-mobile. help please.

 

[dictoresno]

Sounds like it may be a carrier issue in your area. You try calling tmobile?

 

[MrMacMack]

What version of iOS do you have installed? You can try updating roaming list by dialing *228. Not much else other than requesting a bumper from Apple, which I don't think will do anything. Is the phone still within the warranty period?