Unable to obtain Verizon 3G signal

I have a Verizon iPhone 4s that cannot receive a 3G signal. I do see the bars, the Verizon wording, and roaming "O" symbol. I am pretty confident the area I live is has a good signal.

Problem occurred after I replaced the digitizer. I made sure everything was connected and in place prior to powering it up.

I verified the pressure contact was cleaned prior to installing it. I also swapped out a pressure contact from a functional iPhone. Still wasn't able to pick up a 3G signal.

Can anyone advise on next steps to troubleshoot? E.g. Reset all settings perhaps? Upgrade iOs?