I installed a Yosemite 10.10.5 OS to a Macbook Late 2008 model. The OS works fine except for the Audio. I have tried NVRAM reset and SMC Reset but all failed.
The chimes sound does play when the OS boots up, but sound is not available to the OS.
I tried to run this command to check if there's a Audio hardware, and it seems there is:
Macs-MacBook:~ Mac$ system_profiler SPAudioDataType Audio: Intel High Definition Audio: Audio ID: 63 Headphone: Connection: Combination Output Line Input: Connection: Combination Input Speaker: Connection: Internal Internal Microphone: Connection: Internal External Microphone / iPhone Headset: Connection: 1/8-Inch Jack S/PDIF Optical Digital Audio Output: Connection: Combination Output S/PDIF Optical Digital Audio Input: Connection: Combination Input Devices:
What could be wrong? And how can the audio be fixed?