I have an iPhone 3GS 16GB with the carrier Fido. I've had it for 3 years now and never experienced low signal strength. The OS is 5.1 and signal strength was good until about a month ago when i started noticiing that the signal strength is always 3 or less bars and this was never the case before. Even in places i have been before such as work i always used to receive full signal and now its either 2 or "searching." As such it drains my battery and i have no idea why the signal strength just dropped suddenly. Is my sim messed up or the phone itself is showing its age? Any help would be appreciated, thanks