High level of noise in audio output after fixing no sound

[Lukfi]

Hi, I have a machine with Linux Mint 17 MATE and this morning I found out the sound stopped working. Probably a buggy update? I don't know. While trying to fix it as quickly as possible, I reinstalled both pulseaudio and alsa; I followed recommendations from several websites and I don't remember what exactly I have done. Somehow I got sound working again, but with much more noise than before, which makes listening to music very uncomfortable. There's a very audible swishing sound that's amplified by moving the mouse or doing anything on the PC (it's not constant, which makes it so much irritating) that wasn't there before. There's also a higher pitch whirring sound from the power circuitry that was there before, but less audible. Now, frankly, we're talking shitty onboard audio here, the motherboard is quite old and sound quality was pretty questionable as it was, but at least the swishing noise wasn't there. I ask for your help in getting it to the way things were before (in the stock installation) without having to reinstall the OS. Tell me if you need to see the output of any diagnostic commands. Thanks in advance for your replies.

[all41]

Hello Lukfi,

Try booting back to the install iso and boot Mint in the live mode to make sure it's not a hardware problem.

[Lukfi]

Thank you for your excellent suggestion. I booted from a live DVD and the noise is still there and it's about the same intensity. It obviously is a hardware problem. It got this way when I upgraded the processor to a more power hungry model, before that the sound wasn't that bad.

[all41]

Maybe the problem is in the power supply unit. Also check the motherboard for bulging capacitors like in these photos:
https://www.google.com/search?q=bulging ... d=0CB8QsAQ
Best of luck to you.

[Lukfi]

Unfortunately there's little I can do about that, it's my work PC and it belongs to the company. I had it open when I was changing the CPU and indeed there were a couple of leaked capacitors on the motherboard. I have a spare Sound Blaster Live! around here somewhere, so I could plug it in, though I'd hate to lose it in case of a catastrophic power supply failure