Let people know what the fix was.
Some time before that, like maybe a day, I opened my computer to learn and see how everything is connected inside, and that included unplugging some cables. Turns out that I replugged the cable that supports the front panel audio jacks wrongly. There are two cables: HD AUDIO, and AC97 if I remember correctly. I thought that both must be connected, so I plugged the latter into a place, even though it was an imperfect plugging. That caused a very high voltage when connecting electronic devices into the jacks, making the jacks useless. I figured out it was the problem when I started reading about motherboard connections while wondering if it was about these connections, and turns out unsuprisingly that it was. I unplugged the AC97 cable - problem fixed