My sound just stopped working.
It seems to not detect my sound chip:

tf@based-pc:~$ lspci -nnk | grep -i -A7 audio
00:1f.3 Audio device [0403]: Intel Corporation Sunrise Point-LP HD Audio [8086:9d71] (rev 21)
Subsystem: Acer Incorporated [ALI] Sunrise Point-LP HD Audio [1025:1295]
Kernel driver in use: snd_hda_intel
Kernel modules: snd_hda_intel, snd_soc_skl, snd_soc_avs, snd_sof_pci_intel_skl
00:1f.4 SMBus [0c05]: Intel Corporation Sunrise Point-LP SMBus [8086:9d23] (rev 21)
Subsystem: Acer Incorporated [ALI] Sunrise Point-LP SMBus [1025:1295]
Kernel driver in use: i801_smbus
Kernel modules: i2c_i801
01:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTL8411B PCI Express Card Reader [10ec:5287] (rev 01)
tf@based-pc:~$

Alsamixer just has a PCM control and it does say the card is "HDA Intel PCH", but it doesn't show the chip.

Solved, turns out my sound chip stopped working for whatever reason (didn't work on Windows, other Linux boot) , however, going to the BIOS, turning laptop off, then pressing keys to get to advanced BIOS settings, powering laptop on, going to BIOS, going to Advanced, PCH-IO, HD-Audio then setting HD-Audio to Auto (do not save yet) then On then quit+save changes somehow fixed it. I have no idea how/why that fixes it, but that fixed it for me.

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