R50e soundcard fault

[vtwinmark]

Hi, looking for advice on a soundcard fault on the R50e, had a power spike, heard a pop and laptop went blank. Restarted fine, but informs me that no audio device is fitted, we have no sound at all now. I am led to believe that the soundcard is an integral part of the laptop, and not easily (cheaply) replaced. Have been advised to get a external USB soundcard instead. Does this sound correct? Any advice appreciated!