This machine was exposed to liquid and would not start up. It initially presented with corroded left speaker amps, a shorted backlight driver UP800, as well as liquid-damaged trackpad. After cleaning and replacement of speaker amps UR660/UR630/UR600 and UP800 the machine is functional except for audio. The speakers show up as output devices in macOS but they produce no sound. Neither headphones nor microphone work. Any ideas?