Audio not working in dell inspiron

Registration date
Friday November 27, 2015
Last seen
November 27, 2015
My laptop felldown and motherboard was cracked. Service person has changed the motherboard, the laptop is working fine but the audio and network had a problem even after updating the corresponding drivers. He suggested me to change the operating system also. I hv updated to Windows 8, still the problem is continued. Network adapter hardware might have cracked but High definition audio driver is working but im not getting any sound even in headphones.. Please suggest me the solution