Strange humming/buzzing sound in speakers

Hello everyone.

My speakers are MS/ML-T508, and when I turn them on, they are humming very loudly. This problem appeared only when I woke up today and turned on my PC. Everything was fine yesterday.

I included the model of my speakers and the sound they are playing in the attachments (I recorded the sound with my phone, so the quality is kind of bad. If you can't hear anything, turn up the volume on your speakers). Please note that my twin stereo output speakers are fine and the sound is coming from the big box in the middle (Don't know the name of it), and the sound is playing whenever I turn it on (It doesn't matter if it's plugged in the PC or not).

Thanks in advance and if you need any more info on the problem, I'll share it. And feel free to move the thread if it's in the wrong sub-forum. :)

Okay, updated. :)

There are 2 pages when I click on the sound card. The second one says "Realtek High Definition Audio".

UPDATE: They won't turn on anymore. I plugged them out and back in the socket and they won't turn on now, also they seem to produce this strange kind of smell while they were on.

Could it be that they just kicked the bucket? I've had them for over 6 years now.

I've put the speakers away, the smell was too much.

I'm not sure how to check that. The AMD one is disabled in the device manager, and I'm using the Realtek one (As of now, I have headphones plugged in), and I've tested speakers from a friend and they are working just fine. So it's probably time for a replacement. Thanks!