phone still dead after battery replacement

The instructions and tools were great and replacing my iPhone 5s battery went smoothly. The phone had water damage but inside looked pristine with no signs of corrosion. I even took the phone apart twice to make sure I got all the connections tight and in their sockets. Still no response and a dead phone. I of course tried holding the Home and On buttons together for a long time and numerous times. What can I do now. Replace the logic board? Probably not worth it in my mind.