Internal Speakers Not Working

I have an early 2015 MacBook retina a1534 that I just repaired the c-port and replaced some ribbons and the touchpad. Everything is working fine, except the internal speakers. I can plug in headphones and get audio, just nothing through the internal speakers. Internal speakers do show up as an output device. I’ve tried the most common solutions:

1) NVRAM and SCM resets, 2) Created new user, 3) Reseated audio board ribbon cable.

My question is could a damaged audio board and/or ribbon cable affect the internal speakers, even though the headphone output is working properly? Thanks in advance for any insight on this odd issue