Is the logic board or I/O board causing my sound issues?

A couple of weeks ago I was using my mac and suddenly the screen went black and started blinking a picture of a file.

After this incident my computer's sound would not work.

I took it to the apple store, they found that bluetooth sound worked, but my headphones and internal speakers don't.

They also did a systems override and found that the sound still didn't work, confirming that it is a hardware issue.

They also did some sort of hardware test and said some component failed, but I just did the AHT and it said my system was fine.

Also, possibly unrelated, but my computer from time to time will "restart because an error occurred"

Everything else has been working fine.

So should I replace the logic board, replace the i/o board, something else entirely? Is there a place thats cheaper than the 700$ repair apple offered?

Thanks alot