recording cutting in and out problem

[lacunarain]

the first day i used audacity on this computer it worked fine, created a track using three different instruments using line in, and vocal track using microphone. ever since then i've had this problem, mic and line in, where the sound surges. it's about every half second i get noise, and then it cuts out to silence, so on note will hear it, then silence, hear it, then silence. i have tried playing around the buffer, latency correction, sample rate and sample format. occasionaly i would get it to work for about ten seconds, and then back to the surging. i have tried uninstalling and reinstalling, running only audacity so computer is not mutlitasking, no difference. does anyone have any answers? i have a gateway 2.10 ghz dual core laptop with 4gb of memory. what i find very strange is that is worked the first day fine, and now it's not.

[steve]

Hard to picture exactly what you mean. Could you upload a short sample (WAV or FLAC format) somewhere on the internet (for example "sendspace.com") and post a link.

[lacunarain]

http://www.sendspace.com/file/19rhiv

[lacunarain]

that was using line in, i have the same problem even when i speak into the microphone. what i find makes it so strange is that it worked once and never again.

[steve]

Unfortunately I think it's probably a hardware fault on your sound card.
If you amplify the "silence" in the gaps you can tell that it is basically the same sound as should be there, but at a much lower level and very noisy.

[lacunarain]

could it have got damaged? or why is it making this fault, computer is fairly new