Earpiece speaker not working, all other sounds and speaker phone work

I need to know what would cause an iPhone 4s (verizon) earpiece speaker to not function at all. The only way for me to talk on the phone is with speaker phone. The problem started because my earpiece speaker was getting worse and worse, so I replaced it. After I replaced it I had NO SOUND AT ALL from earpiece. I reset network setting and then did a restore on the phone. Still nothing. Figuring I just got a bad part, and that some sound would be better than no sound at all, I put the old speaker back in. Still nothing. Another restore...still no. I took the phone back apart and cleaned all the connections and made sure everything was in its place and clean. When I turn up/down the volume it says "ringer"...so I know it's not stuck in "headphone" mode, but I cleaned the headphone jack too just in case. I am really good with electronics and have fixed many other iPhones with different issues and have a perfect record...except when it comes to my own iPhone. I just can't get this to work and have no idea what the problem could be. I would just like some opinions or suggestions...any advice I receive, if I choose to apply it to my phone I do so at my own risk. I know a lot of people won't give advice based on the fact that they don't want to be held liable. I really just need a clue as to what it might be so I can get this thing fixed. Any help that anyone could offer me would be GREATLY appreciated. I don't have any money to get the phone repaired...but, I will pay through paypal if the advice fixes my phone. I will give whatever I can to show my gratitude. It might only be $25, at the moment that's about all I have. But, if its advice that fixes my phone I will give what I have. I know it's a lot to ask for a cheap price, but it would really help me out. Thank you in advance to anyone who answers this.