said by skbroadband:
Why would the signal be 3 bars, but essentially I can't make/receive calls?
The bars could be representative of the data signal strength rather than the voice signal strength. This happens on my Samsung Droid Charge and S3. Go to the Network Settings screen and look for the 1X/RTT or CDMA signal strength. What value does it say there? It should be some number in the -110 (poor) to -60 (excellent) dBm range.