This is a Macbook Pro A1398 2013 laptop. It had no power up by liquid damage. Replaced its keyboard and cleaned motherboard entirely, it is back to work for most parts, except sound. There is no an internal sound device and no sound with internal speakers and an external ear phone. If plug in an external USB sound adapter, able to get normal sound and the USB sound device shows in Sound Preference window. Is there anyway to fix the problem by configure or reset software/OS? If it is a hardware problem, is there anyway to fix it, such as replace the audio chip or relative components? Motherboard is 820-3332A. Any link to a schematics for 820-3332A?