Audio not recognized, replaced left I/O board, speakers, no progress.

Hi, I have a Macbook Pro A1211. When it boots up, I hear the audio tone, but once booted into OSX, the computer is stuck in digital optical out, and the red light inside my left I/O board is stuck on. I cannot adjust volume, and when I plug in headphones, they dont work.

I tried the resetting PRAM and other basic troubleshooting, I tried the toothpick method, did not help. I proceeded to replace my left I/O board, however once booted into OSX, it was still stuck on Optical Out and the red light is still on. I have tried replacing the speaker assembly, no help. I also reinstalled OSx

I am not sure what else could be wrong- I am getting tired of spending money on new parts. I cannot go to Apple because I have replaced parts myself, including a new bottom case so the serials don't match.

Any thoughts on how to fix this? Feel free to ask any other questions, will try to respond quickly.