>>Problem: do not generate sound or not clear sound.

Potential causes: 

i). Not properly connected speaker with sound card.

ii). Sound card is not properly fixed on expansion slot.

iii). Sound card driver is not properly installed .

iv). Conflict the sound card with other device.

v). Audio cable is not connected between CD ROM and sound card.

vi). Volume levels are low and mute.

vii). Sound card may be damage.

Solutions:

i). Connect the speaker properly.

ii). Fixed the sound card properly.

iii). Install the driver software proplery.

iv). Remove the conflictions of other device.

v). Connect the audio  cable between hard disk and CD ROM and sound card.

vi). Set volume levels properly and remove  the tick mark of the mute.

vii). Change the sound card.

viii). Change speaker.