[Q] Mic stopped working when in Speaker mode topic

I had to disassemble my Note 2 yesterday to clean the proximity sensor, which had stopped working properly. When I put it back together, the MIC stopped working while I am in Speaker mode. The MIC works fine otherwise, but if I put the phone call into Speaker mode, the person on the other end cannot hear me. I disassembled it again to make sure all cables and connectors are plugged in, and they seem to be. Does anyone know how to fix this? I am running Sophisticated. Thanks in advance.