Packard Bell BV IMEDIA 2215 PB80135701

Hi, i have just joint this forum for a friend of mine. He has a Packard Bell
BV IMEDIA 2215 PB80135701 With Vista Home premium 32 bit. He tried to connect his pc up to the TV using a scart one end and a jack plug into the black socket on the back of the PC. Since then i dont know if the damage was caused by that but now he has no sound. Theres a red cross where the speaker should be in the taskbar stating no audio devices fitted (or simular warning) I have on his behalf downloaded
Realtek Audio Driver 6.0.1. 5821 and a chipset driver from Pacard Bells site but its still not recognised. In device manager there are no warning asterisks. Can anyone help me here with this problem. he tells me he has restored the computer back to factory settings and tried deleting the audio drivers hoping Vista would find new hardware on rebooting. He never got a backup disk with the PC So Havng no knowledge of computers he has asked me if i can sort it although my knowledge is limited. Thanks in advance for any advice